Nuveen Insured Municipal Opportunity Fund, Inc.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-06379         

        Nuveen Insured Municipal Opportunity Fund, Inc.         
(Exact name of registrant as specified in charter)


        333 West Wacker Drive, Chicago, Illinois, 60606         

Address of principal executive offices) (Zip code)


Jessica R. Droeger—Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois, 60606         

(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            10/31          

Date of reporting period:          7/31/04         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

Portfolio of Investments (Unaudited)
Nuveen Insured Municipal Opportunity Fund, Inc. (NIO)
July 31, 2004


Principal

Optional Call

Market

Amount (000)

Description(1)

Provisions*

Ratings**

Value


Alabama - 15.8%

 

$

3,815

Alabama Housing Finance Authority, Multifamily Housing Revenue Refunding Bonds, GNMA Collateralized

7/05 at 103.00

Aaa

$    3,971,720

   Royal Hills Apartment Project, Series 1995F, 6.500%, 7/20/30

 

11,000

Special Care Facilities Financing Authority, Birmingham, Alabama, Baptist Medical Centers, Revenue

5/05 at 102.00

AAA

11,494,450

   Bonds, Baptist Health System Inc, Series 1995B, 5.875%, 11/15/20 - MBIA Insured

 

Special Care Facilities Financing Authority, Birmingham, Alabama, Baptist Medical

Centers Revenue Bonds, Baptist Health System Inc, Series 1996A:

7,465

   5.875%, 11/15/19 - MBIA Insured

11/06 at 102.00

AAA

8,101,242

1,750

   5.875%, 11/15/26 - MBIA Insured

11/06 at 102.00

AAA

1,874,390

 

11,175

City Board of Education, Hoover, Alabama, Capital Outlay Tax Anticipation Warrants,

2/11 at 100.00

AAA

11,622,671

   Series 2001, 5.250%, 2/15/22 - MBIA Insured

 

Jefferson County, Alabama, Sewer Revenue Refunding Warrants, Series 1997A:

25,825

   5.375%, 2/01/27 (Pre-refunded to 2/01/07) - FGIC Insured

2/07 at 100.00

AAA

27,681,043

10,195

   5.375%, 2/01/27 - FGIC Insured

2/07 at 100.00

AAA

10,503,399

 

Jefferson County, Alabama, Sewer Revenue Capital Improvement Warrants, Series 1999A:

10,815

   5.000%, 2/01/33 (Pre-refunded to 2/01/09) - FGIC Insured

2/09 at 101.00

AAA

11,789,432

9,790

   5.000%, 2/01/33 (Pre-refunded to 2/01/09) - FGIC Insured

2/09 at 101.00

AAA

10,724,064

12,000

   5.375%, 2/01/36 (Pre-refunded to 2/01/09) - FGIC Insured

2/09 at 101.00

AAA

13,333,440

29,860

   5.750%, 2/01/38 (Pre-refunded to 2/01/09) - FGIC Insured

2/09 at 101.00

AAA

33,647,144

 

18,760

Jefferson County, Alabama, Sewer Revenue Capitol Improvement Warrants, Series 2001A, 5.000%,

2/11 at 101.00

AAA

20,477,666

   2/01/41 (Pre-refunded to 2/01/11) - FGIC Insured

 

Jefferson County, Alabama, Sewer Revenue Capital Improvement Warrants, Series 2002B:

2,500

   5.125%, 2/01/42 (Pre-refunded to 8/01/12) - FGIC Insured

8/12 at 100.00

AAA

2,741,550

2,500

   5.125%, 2/01/42 (Pre-refunded to 8/01/12) - FGIC Insured

8/12 at 100.00

AAA

2,761,575

 

Jefferson County, Alabama, Sewer Revenue Capital Improvement Warrants, Series 2002D:

425

   5.000%, 2/01/38 (Pre-refunded to 8/01/12) - FGIC Insured

8/12 at 100.00

AAA

462,111

1,940

   5.000%, 2/01/38 (Pre-refunded to 8/01/12) - FGIC Insured

8/12 at 100.00

AAA

2,124,843

14,800

   5.000%, 2/01/42 (Pre-refunded to 8/01/12) - FGIC Insured

8/12 at 100.00

AAA

16,210,144

 

5,240

Jefferson County, Alabama, Sewer Revenue Refunding Warrants, Series 2003B, 5.000%, 2/01/41

2/11 at 101.00

AAA

5,754,987

   (Pre-refunded to 2/01/11) - FGIC Insured

 

4,250

Shelby County Board of Education, Alabama, General Obligation Refunding Warrants, Series 1995,

2/05 at 102.00

AAA

4,413,497

   5.875%, 2/01/17 - AMBAC Insured


Alaska - 2.6%

 

11,245

Alaska Housing Finance Corporation, General Mortgage Revenue Bonds, Series 1999A, 6.050%,

6/09 at 100.00

AAA

11,636,438

   6/01/39 - MBIA Insured

 

11,460

Alaska Housing Finance Corporation, Governmental Purpose Bonds, Series 1995A, 5.875%, 12/01/30 -

12/05 at 102.00

AAA

11,843,452

   MBIA Insured

 

2,680

Alaska Housing Finance Corporation, Collateralized Veterans Mortgage Program Bonds, First Series

12/09 at 100.00

AAA

2,782,778

   1999-A2, 6.250%, 6/01/39 (Alternative Minimum Tax)

 

3,190

Alaska Housing Finance Corporation, Collateralized Veterans Mortgage Program Bonds, Series 1999-A1,

12/09 at 100.00

AAA

3,338,431

   6.150%, 6/01/39

 

3,000

Alaska Student Loan Corporation, Student Loan Revenue Bonds, Series 1998A, 5.250%, 7/01/14

7/08 at 100.00

AAA

3,112,650

   (Alternative Minimum Tax) - AMBAC Insured


Arizona - 0.8%

 

1,000

Maricopa County Union High School District 210, Phoenix, Arizona, General Obligation Bonds, Series

7/14 at 100.00

AAA

1,035,970

   2004A, 5.000%, 7/01/22 - FSA Insured

 

6,770

Pima County Industrial Development Authority, Arizona, Lease Obligation Revenue Refunding Bonds,

1/05 at 101.50

AAA

7,132,195

   Tucson Electric Power Company, Series 1988A, 7.250%, 7/15/10 - FSA Insured

 

2,000

Industrial Development Authority of Yuma, Arizona, Hospital Revenue Bonds, Yuma Regional

8/11 at 101.00

AAA

2,263,000

   Medical Centre, Series 2001, 5.500%, 8/01/20 (Pre-refunded to 8/01/11) - FSA Insured


California - 29.2%

 

400

California Housing Finance Agency, Insured Housing Revenue Bonds, Series 1994C, 6.250%, 8/01/25 -

8/04 at 102.00

AAA

408,324

   MBIA Insured

 

California Rural Home Mortgage Finance Authority, GNMA Single Family Mortgage Revenue Bonds,

Mortgage-Backed Securities Program, Series 1996A:

215

   7.550%, 11/01/26 (Alternative Minimum Tax)

No Opt. Call

AAA

218,079

170

   7.750%, 5/01/27 (Alternative Minimum Tax)

No Opt. Call

AAA

172,489

 

4,500

California, General Obligation Bonds, Series 1998, 5.000%, 10/01/19 - FGIC Insured

10/08 at 101.00

AAA

4,640,355

 

10,000

California Department of Veterans Affairs, Home Purchase Revenue Bonds, Series 2002A, 5.300%,

6/12 at 101.00

AAA

10,436,500

   12/01/21 - AMBAC Insured

 

4,135

California Housing Finance Agency, Home Mortgage Revenue Bonds, Series 2000Y, 0.000%, 8/01/20

11/10 at 55.40

AAA

1,632,209

   (Alternative Minimum Tax) - FSA Insured

 

California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A:

30,000

   5.375%, 5/01/17 - XLCA Insured

5/12 at 101.00

AAA

32,641,500

35,000

   5.375%, 5/01/18 - AMBAC Insured

5/12 at 101.00

AAA

37,888,200

 

20,000

Cucamonga County Water District, California, Certificates of Participation, Water Shares

9/11 at 101.00

AAA

20,149,200

   Purchase, Series 2000, 5.125%, 9/01/35 - FGIC Insured

 

5,500

Fallbrook Union High School District, San Diego County, California, General Obligation

9/04 at 102.00

AAA

5,634,255

   Bonds, Series 1994A, 6.250%, 9/01/19 (Pre-refunded to 9/01/04) - MBIA Insured

 

5,000

Long Beach Bond Financing Authority, California, Lease Revenue Refunding Bonds, Long Beach Aquarium

11/11 at 101.00

AAA

5,115,500

   of the South Pacific, Series 2001, 5.250%, 11/01/30 - AMBAC Insured

 

20,000

Los Angeles Unified School District, Los Angeles County, California, General Obligation Bonds,

7/13 at 100.00

AAA

20,794,400

   Series 2003A, 5.000%, 7/01/21 - FSA Insured

 

9,000

Orange County, California, Refunding Recovery Bonds, Series 1995A, 5.750%, 6/01/15 - MBIA Insured

6/05 at 102.00

AAA

9,449,730

 

12,500

Orange County, California, Recovery Certificates of Participation, Series 1996A, 6.000%, 7/01/26 -

7/06 at 102.00

AAA

13,459,500

   MBIA Insured

 

6,205

Port of Oakland, California, Revenue Bonds, Series 2002L, 5.000%, 11/01/22 (Alternative Minimum

11/12 at 100.00

AAA

6,277,723

   Tax) - FGIC Insured

 

Poway Redevelopment Agency, California, Tax Allocation Bonds, Paguay Redevelopment Project,

Series 2001:

15,000

   5.200%, 6/15/30 - AMBAC Insured

12/11 at 101.00

AAA

15,271,200

5,000

   5.125%, 6/15/33 - AMBAC Insured

12/11 at 101.00

AAA

5,043,750

 

6,000

Redlands Unified School District, San Bernardino County, California, General Obligation Bonds,

7/13 at 100.00

AAA

6,049,140

   Series 2003, 5.000%, 7/01/26 - FSA Insured

 

11,000

Sacramento Municipal Utility District, California, Electric Revenue Bonds, Series 2003R, 5.000%,

8/13 at 100.00

AAA

11,019,580

   8/15/33 - MBIA Insured

 

19,300

Sacramento Power Authority, California, Revenue Bonds, Power Authority Cogeneration Project, Series

7/06 at 102.00

AAA

20,909,427

   1995, 5.875%, 7/01/15 - MBIA Insured

 

6,500

Salinas, California, GNMA Collateralized Housing Facility Revenue Refunding Bonds, Villa Serra

1/05 at 102.00

AAA

6,636,695

   Project, Series 1994A, 6.600%, 7/20/30

 

10,000

San Francisco Airports Commission, California, Revenue Bonds, San Francisco International Airport,

5/06 at 101.00

AAA

10,248,900

   Second Series, Issue 13B, 5.500%, 5/01/26 (Alternative Minimum Tax) - MBIA Insured

 

13,710

San Francisco Airports Commission, California, Revenue Refunding Bonds, San Francisco International

5/11 at 100.00

AAA

13,836,818

   Airport, Second Series, 2001 Issue 27A, 5.250%, 5/01/26 (Alternative Minimum Tax) - MBIA Insured

 

11,500

San Francisco Bay Area Rapid Transit District, California, Sales Tax Revenue Bonds, Series 2001,

7/11 at 100.00

AAA

11,603,500

   5.125%, 7/01/36 - AMBAC Insured

 

66,685

San Joaquin Hills Transportation Corridor Agency, Orange County, California, Senior Lien Toll Road

No Opt. Call

AAA

29,615,475

   Revenue Bonds, 0.000%, 1/01/21

 

San Joaquin Hills Transportation Corridor Agency, Orange County, California, Toll Road

Revenue Refunding Bonds, Series 1997A:

31,615

   5.250%, 1/15/30 - MBIA Insured

1/07 at 102.00

AAA

32,109,459

21,500

   0.000%, 1/15/32 - MBIA Insured

No Opt. Call

AAA

4,625,080

 

12,525

San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Area Redevelopment Project,

8/10 at 101.00

AAA

12,931,812

   Series 2002, 5.000%, 8/01/20 - MBIA Insured

 

11,000

Santa Ana Financing Authority, California, Police Administration and Housing Facility, Lease

No Opt. Call

AAA

13,112,770

   Revenue Bonds, Series 1994A, 6.250%, 7/01/24 - MBIA Insured

 

5,500

Santa Clara County Financing Authority, California, Lease Revenue Bonds, VMC Facility Replacement

11/04 at 102.00

AAA

5,699,430

   Project, 1994 Series A, 6.750%, 11/15/20 (Pre-refunded to 11/15/04) - AMBAC Insured


Colorado - 6.4%

 

10,000

Denver City and County, Colorado, Airport System Revenue Refunding Bonds, Series 2001A, 5.500%,

11/11 at 100.00

AAA

10,847,100

   11/15/15 (Alternative Minimum Tax) - FGIC Insured

 

10,545

Denver City and County, Colorado, Airport System Revenue Bonds, Series 1996D, 5.500%, 11/15/25 -

11/06 at 101.00

AAA

11,022,689

   MBIA Insured

 

6,200

Denver Convention Center Hotel Authority, Colorado, Convention Center Hotel Senior Revenue Bonds,

12/13 at 100.00

AAA

6,194,854

   Series 2003A, 5.000%, 12/01/33 - XLCA Insured

 

35,995

E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 1997B, 0.000%, 9/01/23 -

No Opt. Call

AAA

13,018,672

   MBIA Insured

 

30,800

E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 2000A, 5.750%, 9/01/35 -

9/10 at 102.00

AAA

33,180,224

   MBIA Insured

 

11,800

E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 2000B, 0.000%, 9/01/15 -

9/10 at 74.80

AAA

6,620,744

   MBIA Insured


District of Columbia - 1.4%

 

2,720

District of Columbia Housing Finance Agency, GNMA Collateralized Single Family Mortgage Revenue

12/04 at 100.00

AAA

2,728,187

   Bonds, Series 1990B, 7.100%, 12/01/24 (Alternative Minimum Tax)

 

District of Columbia Water and Sewer Authority, Public Utility Revenue Bonds, Subordinate Lien

Series 2003:

5,000

   5.125%, 10/01/24 - FGIC Insured

10/13 at 100.00

AAA

5,125,750

5,000

   5.125%, 10/01/25 - FGIC Insured

10/13 at 100.00

AAA

5,107,150

 

4,840

Metropolitan Washington D.C. Airports Authority, Airport System Revenue Bonds, Series 2001A,

10/11 at 101.00

AAA

5,151,164

   5.500%, 10/01/19 (Alternative Minimum Tax) - MBIA Insured


Florida - 5.8%

 

4,425

Jacksonville Economic Development Commission, Florida, Healthcare Facilities Revenue Bonds, Mayo

11/12 at 100.00

AAA

4,641,604

   Clinic, Series 2001C, 5.500%, 11/15/36 - MBIA Insured

 

1,505

Lee County, Florida, Transportation Facilities Revenue Bonds, Series 2004B, 5.000%, 10/01/21 -

10/14 at 100.00

AAA

1,572,650

   AMBAC Insured

 

35,920

Miami-Dade County, Florida, Aviation Revenue Bonds, Miami International Airport, Series 2002,

10/12 at 100.00

AAA

36,402,765

   5.375%, 10/01/32 (Alternative Minimum Tax) - FGIC Insured

 

Miami Dade County, Florida, Aviation Revenue Bonds, Miami International Airport, Series 2002A:

18,500

   5.000%, 10/01/33 (Alternative Minimum Tax) - FSA Insured

10/12 at 100.00

AAA

17,986,810

2,150

   5.125%, 10/01/35 (Alternative Minimum Tax) - FSA Insured

10/12 at 100.00

AAA

2,124,437

 

3,000

Orange County, Florida, Solid Waste Facility Revenue Refunding Bonds, Series 2003, 5.000%,

10/13 at 100.00

AAA

3,206,130

   10/01/14 - MBIA Insured

 

Plantation, Florida, Non-Ad Valorem Revenue Bonds, Refunding and Improvement Projects, Series 2003:

2,010

   5.000%, 8/15/16 - FSA Insured

8/13 at 100.00

Aaa

2,150,981

2,110

   5.000%, 8/15/17 - FSA Insured

8/13 at 100.00

Aaa

2,243,204

2,225

   5.000%, 8/15/18 - FSA Insured

8/13 at 100.00

Aaa

2,351,714


Georgia - 0.7%

 

Fulton County Development Authority, Georgia, Revenue Bonds, Georgia Tech Molecular Science

Building Project, Series 2004:

1,695

   5.250%, 5/01/19 - MBIA Insured

5/14 at 100.00

AAA

1,826,956

1,135

   5.250%, 5/01/20 - MBIA Insured

5/14 at 100.00

AAA

1,217,742

 

5,000

Glynn-Brunswick Memorial Hospital Authority, Georgia, Revenue Bonds, Southeast Georgia Health

8/06 at 102.00

AAA

5,372,850

   Systems Project, Series 1996, 5.250%, 8/01/13 - MBIA Insured


Hawaii - 2.0%

 

24,250

Hawaii Department of Budget and Finance, Special Purpose Revenue Bonds, Hawaii Electric Company

5/06 at 101.00

AAA

25,850,500

   Inc. and Subsidiaries Project, Series 1996A, 6.200%, 5/01/26 (Alternative Minimum Tax) - MBIA

   Insured


Idaho - 0.3%

 

1,070

Idaho Housing Agency, Single Family Mortgage Bonds, Series 1994B-1, 6.750%, 7/01/22

No Opt. Call

Aa1

1,089,688

 

970

Idaho Housing Agency, Single Family Mortgage Bonds, Series 1994B-2, 6.900%, 7/01/26 (Alternative

No Opt. Call

Aa1

1,037,270

   Minimum Tax)

 

1,150

Idaho Housing Agency, Single Family Mortgage Bonds, Senior Lien, Series 1995 B, 6.600%, 7/01/27

1/05 at 102.00

Aaa

1,177,888

   (Alternative Minimum Tax)


Illinois - 9.0%

 

1,050

Bedford Park Village, Illinois, General Obligation Bonds, Series 2004A, 5.250%, 12/15/20 - FSA

12/14 at 100.00

AAA

1,125,002

   Insured

 

12,500

Chicago, Illinois, General Airport Second Lien Revenue Refunding Bonds, O'Hare International

1/05 at 101.00

AAA

12,773,250

   Airport, Series 1993C, 5.000%, 1/01/18 - MBIA Insured

 

Chicago, Illinois, Second Lien Passenger Facility Charge Revenue Refunding Bonds, O'Hare

International Airport, Series 2001E:

4,615

   5.500%, 1/01/17 (Alternative Minimum Tax) - AMBAC Insured

1/11 at 101.00

AAA

4,947,788

4,870

   5.500%, 1/01/18 (Alternative Minimum Tax) - AMBAC Insured

1/11 at 101.00

AAA

5,196,387

 

12,000

Cook County, Illinois, General Obligation Refunding Bonds, Series 2003, 5.000%, 11/15/10 - MBIA

No Opt. Call

AAA

13,077,240

   Insured

 

5,000

Community Unit School District No. 204, Indian Prairie, DuPage and Will Counties, Illinois,

12/11 at 100.00

AAA

5,286,750

   General Obligation Bonds, Series 2001, 5.000%, 12/30/15 - FGIC Insured

 

Eastern Illinois University, Auxiliary Facilities System Revenue Bonds, Series 1989:

12,355

   0.000%, 10/01/09 - MBIA Insured

10/04 at 74.08

AAA

9,125,156

16,470

   0.000%, 4/01/16 (Pre-refunded to 10/01/04) - MBIA Insured

10/04 at 47.07

AAA

7,735,465

 

10,000

Illinois Development Finance Authority, Revenue Bonds, Provena Health, Series 1998A, 5.500%,

5/08 at 101.00

AAA

10,490,500

   5/15/21 - MBIA Insured

 

2,095

Illinois Educational Facilities Authority, Revenue Bonds, Robert Morris College, Series 2000,

12/07 at 100.00

Aaa

2,246,594

   5.800%, 6/01/30 - MBIA Insured

 

2,180

Illinois Educational Facilities Authority, Revenue Bonds, DePaul University, Series 2000, 5.500%,

10/10 at 101.00

AAA

2,466,714

   10/01/19 (Pre-refunded to 10/01/10) - AMBAC Insured

 

7,000

Illinois Health Facilities Authority, Revenue Bonds, Hospital Sisters Services Inc. Obligated

6/08 at 101.00

Aaa

7,190,330

   Group, Series 1998A, 5.000%, 6/01/18 - MBIA Insured

 

4,500

Illinois Health Facilities Authority, Revenue Bonds, Alexian Brothers Health System, Series 1999,

1/09 at 101.00

AAA

4,607,685

   5.000%, 1/01/19 - FSA Insured

 

22,410

Illinois, General Obligation Bonds, Illinois FIRST Program, Series 2002, 5.125%, 2/01/27 - FGIC

2/12 at 100.00

AAA

22,772,594

   Insured

 

4,560

Macon County, Illinois, Revenue Bonds, Millikin University, Series 1995, 6.250%, 10/01/16

10/05 at 100.00

AAA

4,804,279

   (Pre-refunded to 10/01/05) - AMBAC Insured


Indiana - 3.7%

 

2,030

Decatur Township Multi-School Building Corporation, Marion County, Indiana, First Mortgage Bonds,

7/13 at 100.00

AAA

2,103,364

   Series 2003, 5.000%, 7/15/20 - FGIC Insured

 

11,000

Indiana Health Facility Financing Authority, Hospital Revenue Bonds, Daughters of Charity, Series

5/06 at 100.00

Aaa

11,256,850

   1993, 5.750%, 11/15/22

 

4,035

Indiana State Office Building Commission, Facilities Revenue Bonds, Indiana State Museum, Series

No Opt. Call

AAA

4,430,712

   2004C, 5.250%, 7/01/15 - FGIC Insured

 

3,250

Indianapolis Local Public Improvement Bond Bank, Indiana, Waterworks Project, Series 2002A,

7/12 at 100.00

AAA

3,322,702

   5.250%, 7/01/33 - MBIA Insured

 

20,000

Indianapolis Local Public Improvement Bond Bank, Indiana, Series 1999E, 0.000%, 2/01/28 - AMBAC

No Opt. Call

AAA

5,350,000

   Insured

 

1,340

Monroe-Gregg Grade School Building Corporation, Morgan County, Indiana, First Mortgage Bonds,

1/14 at 100.00

AAA

1,350,519

   Series 2004, 5.000%, 1/15/25 - FSA Insured

 

5,000

Noblesville, Indiana, Redevelopment Authority Economic Development Lease Rental Bonds, Exit

7/13 at 100.00

AAA

4,985,500

   10 Project, Series 2003, 5.000%, 1/15/28 - AMBAC Insured

 

10,000

Trustees of Purdue University, Indiana, Purdue University Student Fee Bonds, Series O, 5.000%,

1/12 at 100.00

AAA

10,385,600

   7/01/19 - MBIA Insured

 

3,705

Whitley County Middle School Building Corporation, Columbia City, Indiana, First Mortgage Bonds,

7/13 at 100.00

AAA

3,937,118

   Series 2003, 5.000%, 7/15/16 - FSA Insured


Iowa - 0.3%

 

3,045

Ames, Iowa, Hospital Revenue Refunding Bonds, Mary Greeley Medical Center, Series 2003, 5.000%,

6/13 at 100.00

Aaa

3,212,231

   6/15/15 - AMBAC Insured


Kansas - 0.4%

 

5,000

University of Kansas Hospital Authority, Health Facilities Revenue Bonds, KU Health System, Series

9/09 at 100.00

AAA

5,214,300

   1999A, 5.650%, 9/01/29 - AMBAC Insured


Kentucky - 1.4%

 

3,870

Kenton County School District Finance Corporation, Kentucky, School Building Revenue Bonds, Series

6/14 at 100.00

Aaa

4,042,525

   2004, 5.000%, 6/01/20 - MBIA Insured

 

12,980

Louisville and Jefferson County Metropolitan Sewer District, Kentucky, Sewer and Drainage System

11/11 at 101.00

AAA

13,682,478

   Revenue Bonds, Series 2001A, 5.500%, 5/15/34 - MBIA Insured


Louisiana - 1.6%

 

5,000

De Soto Parish, Louisiana, Pollution Control Revenue Refunding Bonds, Cleco Utility Group Inc.

9/09 at 102.00

AAA

5,452,250

   Project, Series 1999, 5.875%, 9/01/29 - AMBAC Insured

 

3,025

Lafayette, Louisiana, Utilities Revenue Bonds, Series 2004, 5.250%, 11/01/22 (WI, settling 8/10/04) -

11/14 at 100.00

AAA

3,210,765

   MBIA Insured

 

7,305

Orleans Levee District, Louisiana, Levee District General Obligation Bonds, Series 1986, 5.950%,

12/05 at 103.00

AAA

7,882,241

   11/01/15 - FSA Insured

 

3,000

St. Charles Parish, Louisiana, Pollution Control Revenue Bonds, Louisiana Power and Light Company,

12/04 at 100.00

AAA

3,083,100

   Series 1991, 7.500%, 6/01/21 (Alternative Minimum Tax) - FSA Insured


Maine - 0.2%

 

3,000

Maine Health and Higher Educational Facilities Authority, Revenue Bonds, Series 2003B, 5.000%,

7/13 at 100.00

AAA

3,013,380

   7/01/28 - FSA Insured


Massachusetts - 6.6%

 

22,500

Massachusetts Development Finance Authority, Revenue Bonds, WGBH Educational Foundation, Series

1/12 at 101.00

AAA

23,152,275

   2002A, 5.375%, 1/01/42 - AMBAC Insured

 

8,400

Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Berkshire Health Systems,

10/05 at 102.00

AAA

8,954,904

   Series 1995D, 6.000%, 10/01/13 - MBIA Insured

 

1,180

Massachusetts Housing Finance Agency, Housing Revenue Refunding Bonds, Series 1995A, 6.100%,

12/05 at 102.00

AAA

1,223,861

   12/01/16 - MBIA Insured

 

15,000

Massachusetts, Special Obligation Dedicated Tax Revenue Bonds, Series 2004, 5.250%, 1/01/23 - FGIC

1/14 at 100.00

AAA

15,790,650

   Insured

 

33,315

Massachusetts Turnpike Authority, Metropolitan Highway System Revenue Bonds, Senior Series 1997A,

1/07 at 102.00

AAA

33,075,465

   5.000%, 1/01/37 - MBIA Insured

 

1,500

University of Massachusetts Building Authority, Senior Lien Project Revenue Bonds, Series 2004-1,

11/14 at 100.00

AAA

1,633,110

   5.375%, 11/01/20 - AMBAC Insured


Michigan - 7.5%

 

6,000

Detroit, Michigan, General Obligation Bonds, Series 2001A-1, 5.375%, 4/01/18 - MBIA Insured

10/11 at 100.00

AAA

6,475,320

 

5,490

Detroit City School District, Wayne County, Michigan, Unlimited Tax School Building and Site

No Opt. Call

AAA

6,389,317

   Improvement Bonds, Series 2001A, 6.000%, 5/01/29 - FSA Insured

 

Detroit, Michigan, Sewerage Disposal System Revenue Bonds, Series 1999A:

15,825

   5.750%, 7/01/26 (Pre-refunded to 1/01/10) - FGIC Insured

1/10 at 101.00

AAA

17,980,682

20,000

   5.875%, 7/01/27 (Pre-refunded to 1/01/10) - FGIC Insured

1/10 at 101.00

AAA

22,848,000

 

8,700

Detroit, Michigan, Water Supply System Revenue Senior Lien Bonds, Series 1997-A, 5.000%,

7/07 at 101.00

AAA

8,714,355

   7/01/27 - MBIA Insured

 

8,000

Gaylord Community Schools, Ostego and Antrim Counties, Michigan, School Building and Site and

5/07 at 37.75

AAA

2,805,360

   Refunding Bonds, Series 1992, 0.000%, 5/01/21 (Pre-refunded to 5/01/07) - MBIA Insured

 

Grand Rapids Community College, Kent County, Michigan, General Obligation Refunding Bonds,

Series 2003:

1,050

   5.250%, 5/01/17 - AMBAC Insured

5/13 at 100.00

AAA

1,134,378

1,085

   5.250%, 5/01/20 - AMBAC Insured

5/13 at 100.00

AAA

1,157,413

 

27,000

Okemos Public School District, Ingham County, Michigan, School Building and Site Bonds, Series

5/06 at 34.54

AAA

8,986,680

   1991I, 0.000%, 5/01/21 (Pre-refunded to 5/01/06) - MBIA Insured

 

10,000

Wayne County, Michigan, Limited Tax General Obligation Airport Hotel Revenue Bonds, Detroit

12/11 at 101.00

AAA

10,385,600

   Metropolitan Wayne County Airport, Series 2001A, 5.250%, 12/01/25 - MBIA Insured

 

6,850

Wayne County, Michigan, Airport Revenue Bonds, Detroit Metropolitan Airport, Series 1998A, 5.375%,

12/08 at 101.00

AAA

7,296,620

   12/01/15 (Alternative Minimum Tax) - MBIA Insured


Minnesota - 1.1%

 

13,020

St. Paul Housing and Redevelopment Authority, Minnesota, GNMA Collateralized Mortgage Loan

12/11 at 102.00

Aaa

13,524,134

   Multifamily Housing Revenue Bonds, Marian Center GEAC Project, Series 2001A, 3.870%, 6/20/43


Nevada - 6.5%

 

Director of Nevada State Department of Business and Industry, Revenue Bonds, Las Vegas Monorail

Project, First Tier Series 2000:

15,000

   5.625%, 1/01/34 - AMBAC Insured

1/10 at 102.00

AAA

15,926,550

13,000

   5.375%, 1/01/40 - AMBAC Insured

1/10 at 100.00

AAA

13,290,290

 

825

Nevada Housing Division, Single Family Mortgage Bonds, Senior Series 1994B-1, 6.700%, 10/01/17

10/04 at 102.00

Aa2

842,606

 

635

Nevada Housing Division, Single Family Mortgage Bonds, Senior Series 1994B-2, 6.950%, 10/01/26

10/04 at 102.00

Aa2

640,321

   (Alternative Minimum Tax)

 

40,285

Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.375%, 6/01/32 - FGIC Insured

6/12 at 100.00

AAA

41,560,020

 

10,000

Reno, Nevada, Sales and Room Tax Revenue Bonds, Reno Transportation Rail Access Corridor Project,

6/12 at 100.00

AAA

10,139,700

   Senior Lien Series 2002, 5.125%, 6/01/27 - AMBAC Insured


New York - 7.1%

 

8,685

Long Island Power Authority, New York, Electric System General Revenue Bonds, Series 1998A,

6/08 at 101.00

AAA

9,366,251

   5.300%, 12/01/19 - FSA Insured

 

Metropolitan Transportation Authority, New York, State Service Contract Refunding Bonds,

Series 2002A:

2,500

   5.000%, 7/01/21 - FGIC Insured

7/12 at 100.00

AAA

2,591,675

5,000

   5.000%, 7/01/25 - FGIC Insured

7/12 at 100.00

AAA

5,076,550

 

15,000

New York City Municipal Water Finance Authority, New York, Water and Sewerage System Revenue Bonds,

6/06 at 101.00

AAA

15,290,700

   Fiscal Series 1997A, 5.375%, 6/15/26 - FSA Insured

 

New York City Municipal Water Finance Authority, New York, Water and Sewerage System Revenue Bonds,

Fiscal Series 1996B:

3,520

   5.750%, 6/15/26 (Pre-refunded to 6/15/06) - MBIA Insured

6/06 at 101.00

AAA

3,805,226

6,480

   5.750%, 6/15/26 - MBIA Insured

6/06 at 101.00

AAA

6,956,345

 

5,000

New York State Urban Development Corporation, Correctional Capital Facilities Revenue Bonds, Series

1/07 at 102.00

AAA

5,503,000

   1996-7, 5.700%, 1/01/27 (Pre-refunded to 1/01/07) - MBIA Insured

 

15,600

Port Authority of New York and New Jersey, Consolidated Bonds, Ninety-Seventh Series, 6.650%,

1/05 at 101.00

AAA

16,086,252

   1/15/23 (Alternative Minimum Tax) - FGIC Insured

 

25,000

Triborough Bridge and Tunnel Authority, New York, Subordinate Lien General Revenue Refunding Bonds,

11/12 at 100.00

AAA

25,023,250

   Series 2002E, 5.000%, 11/15/32 - MBIA Insured


North Carolina - 0.4%

 

5,000

North Carolina Municipal Power Agency 1, Catawba Electric Revenue Bonds, Series 2003A, 5.250%,

1/13 at 100.00

AAA

5,392,800

   1/01/16 - FSA Insured


Ohio - 3.9%

 

2,650

Cleveland State University, Ohio, General Receipts Bonds, Series 2004, 5.250%, 6/01/24 (WI, settling

6/14 at 100.00

AAA

2,779,532

   8/05/04) - FGIC Insured

 

2,000

Columbus City School District, Franklin County, Ohio, General Obligation Bonds, Series 2004,

12/14 at 100.00

AAA

2,088,280

   5.250%, 12/01/25 - FSA Insured

 

20,100

Lucas County, Ohio, Hospital Revenue Bonds, ProMedica Healthcare Obligated Group, Series 1999,

11/09 at 101.00

AAA

20,336,376

   5.375%, 11/15/39 - AMBAC Insured

 

1,725

Ohio Housing Finance Agency, GNMA Mortgage-Backed Securities Program Residential Mortgage Revenue

3/05 at 102.00

Aaa

1,731,745

   Bonds, Series 1995A-2, 6.625%, 3/01/26 (Alternative Minimum Tax)

 

Ohio Air Quality Development Authority, Revenue Refunding Bonds, JMG Funding Limited Partnership

Project, Series 1994:

13,750

   6.375%, 1/01/29 (Alternative Minimum Tax) - AMBAC Insured

10/04 at 102.00

AAA

14,119,050

8,000

   6.375%, 4/01/29 (Alternative Minimum Tax) - AMBAC Insured

10/04 at 102.00

AAA

8,214,720


Oklahoma - 1.5%

 

7,670

Oklahoma Housing Finance Agency, GNMA Collateralized Single Family Mortgage Revenue Bonds, Series

No Opt. Call

AAA

7,993,674

   1987A, 7.997%, 8/01/18 (Alternative Minimum Tax)

 

5,245

Oklahoma State Industries Authority, Revenue Bonds, Oklahoma Medical Research Foundation, Series

2/11 at 100.00

Aaa

5,469,171

   2001, 5.250%, 2/01/21 - AMBAC Insured

 

4,880

University of Oklahoma Board of Regents, Housing Revenue Bonds, Series 2004, 5.000%, 7/01/22 -

7/14 at 100.00

Aaa

5,035,867

   AMBAC Insured


Oregon - 0.5%

 

3,985

Oregon Department of Transportation, Highway User Tax Revenue Bonds, Series 2004A, 5.000%,

11/04 at 100.00

AA+

4,189,351

   11/15/20

 

1,885

Oregon Housing and Community Services Department, Mortgage Revenue Bonds, Single-Family

7/05 at 102.00

Aa2

1,939,156

   Mortgage Program, Series 1995A, 6.450%, 7/01/26 (Alternative Minimum Tax)


Puerto Rico - 0.2%

 

2,000

Puerto Rico Highway and Transportation Authority, Transportation Revenue Bonds, Series 2003G,

7/13 at 100.00

AAA

2,166,420

   5.250%, 7/01/19 - FGIC Insured


Rhode Island - 2.0%

 

2,195

Providence Housing Development Corporation, Rhode Island, FHA-Insured Mortgage Revenue Refunding

1/05 at 102.00

AAA

2,241,446

   Bonds, Barbara Jordan Apartments, Series 1994A, 6.750%, 7/01/25 - MBIA Insured

 

20,475

Rhode Island Depositors Economic Protection Corporation, Special Obligation Refunding Bonds,

2/11 at 100.00

AAA

22,644,326

   Series 1992B, 5.250%, 8/01/21 (Pre-refunded to 2/01/11) - MBIA Insured


South Carolina - 3.7%

 

10,000

Beaufort County, South Carolina, Tax Increment Bonds, New River Redevelopment Project, Series 2002,

12/12 at 100.00

AAA

10,073,900

   5.000%, 6/01/27 - MBIA Insured

 

Piedmont Municipal Power Agency, South Carolina, Electric Revenue Refunding Bonds, Series 1988:

9,190

   0.000%, 1/01/13 (Pre-refunded to 7/01/09) - AMBAC Insured

7/09 at 76.63

AAA

5,960,542

12,810

   0.000%, 1/01/13 - AMBAC Insured

No Opt. Call

AAA

8,594,357

 

South Carolina JOBS Economic Development Authority, Hospital Revenue Bonds, Oconee Memorial

Hospital Inc., Series 1995:

3,000

   6.150%, 3/01/15 - CONNIE LEE/AMBAC Insured

3/05 at 102.00

AAA

3,129,780

600

   6.150%, 3/01/25 - CONNIE LEE/AMBAC Insured

3/05 at 102.00

AAA

624,960

 

8,000

South Carolina Jobs-Economic Development Authority, Industrial Revenue Bonds, South Carolina

11/12 at 100.00

AAA

8,207,120

   Electric and Gas Company Project, Series 2002A, 5.200%, 11/01/27 - AMBAC Insured

 

10,000

South Carolina Jobs-Economic Development Authority, Industrial Revenue Bonds, South Carolina

11/12 at 100.00

AAA

10,241,300

   Electric and Gas Company Project, Series 2002B, 5.450%, 11/01/32 (Alternative Minimum Tax) - AMBAC

   Insured


Tennessee - 0.5%

 

6,455

Memphis-Shelby County Airport Authority, Tennessee, Airport Revenue Bonds, Series 2001A, 5.500%,

3/11 at 100.00

AAA

6,891,487

   3/01/18 (Alternative Minimum Tax) - FSA Insured


Texas - 18.9%

 

Austin, Texas, General Obligation Bonds, Series 2002:

2,150

   5.375%, 9/01/18 - MBIA Insured

9/12 at 100.00

AAA

2,328,966

2,250

   5.375%, 9/01/19 - MBIA Insured

9/12 at 100.00

AAA

2,426,063

 

22,650

Brazos River Authority, Texas, Revenue Refunding Bonds, Houston Industries Inc., Series 1998C,

5/08 at 102.00

AAA

23,694,165

   5.125%, 5/01/19 (Optional put 5/01/08) - AMBAC Insured

 

1,181

Capital Area Housing Finance Corporation, Texas, FNMA-Backed Single Family Mortgage Revenue

4/12 at 106.00

AAA

1,262,462

   Refunding Bonds, Series 2002A-2, 6.300%, 4/01/35 (Alternative Minimum Tax) - AMBAC Insured

 

11,460

Dallas County Utility and Reclamation District, Texas, Unlimited Tax Refunding Bonds, Series 1999B,

2/05 at 100.00

AAA

11,663,530

   5.875%, 2/15/29 - AMBAC Insured

 

12,500

Dallas-Fort Worth International Airport, Texas, Joint Revenue Bonds, Series 2000A, 6.125%,

11/09 at 100.00

AAA

13,438,625

   11/01/35 (Alternative Minimum Tax) - FGIC Insured

 

25,000

Harris County-Houston Sports Authority, Texas, Junior Lien Revenue Refunding Bonds, Series 2001B,

11/11 at 100.00

AAA

25,159,000

   5.250%, 11/15/40 - MBIA Insured

 

Harris County, Texas, Toll Road Senior Lien Revenue Bonds, Series 1989:

9,000

   0.000%, 8/15/18 (Pre-refunded to 8/15/09) - AMBAC Insured

8/09 at 53.84

AAA

4,076,730

39,000

   0.000%, 8/15/19 (Pre-refunded to 8/15/09) - AMBAC Insured

8/09 at 50.26

AAA

16,491,150

7,280

   0.000%, 8/15/20 (Pre-refunded to 8/15/09) - AMBAC Insured

8/09 at 46.91

AAA

2,873,707

5,085

   0.000%, 8/15/21 (Pre-refunded to 8/15/09) - AMBAC Insured

8/09 at 43.80

AAA

1,873,772

 

2,130

Harris County Health Facilities Development Corporation, Texas, Thermal Utility Revenue Bonds, TECO

11/13 at 100.00

AAA

2,248,087

   Project, Series 2003, 5.000%, 11/15/15 - MBIA Insured

 

6,570

Houston, Texas, General Obligation Public Improvement Bonds, Series 2001A, 5.375%, 3/01/19 - FSA

3/11 at 100.00

AAA

7,070,963

   Insured

 

4,170

Houston, Texas, Airport System Subordinate Lien Revenue Bonds, Series 2000B, 5.500%, 7/01/30 - FSA

7/10 at 100.00

AAA

4,351,187

   Insured

 

8,225

Houston, Texas, Airport System Subordinate Lien Revenue Refunding Bonds, Series 1997, 5.125%,

7/07 at 100.00

AAA

8,458,097

   7/01/22 - FGIC Insured

 

17,500

Houston, Texas, Hotel Occupancy Tax and Special Revenue Bonds, Convention and Entertainment

9/11 at 100.00

AAA

17,815,000

   Project, Series 2001B, 5.250%, 9/01/33 - AMBAC Insured

 

12,826

Houston Housing Finance Corporation, Texas, GNMA Collateralized Mortgage Multifamily Housing

9/11 at 105.00

Aaa

13,352,892

   Revenue Bonds, RRG Apartments Project, Series 2001, 6.350%, 3/20/42

 

Houston, Texas, First Lien Combined Utility System Revenue Bonds, Series 2004A:

4,000

   5.250%, 5/15/24 - FGIC Insured

5/14 at 100.00

AAA

4,178,760

5,000

   5.250%, 5/15/25 - MBIA Insured

5/14 at 100.00

AAA

5,203,500

 

23,865

Jefferson County, Texas, Health Facilities Development Corporation, FHA-Insured Mortgage Revenue

8/11 at 100.00

AAA

24,394,803

   Bonds, Baptist Hospital of Southeast Texas, Series 2001, 5.500%, 8/15/41 - AMBAC Insured

 

8,205

Lower Colorado River Authority, Texas, Refunding and Improvement Revenue Bonds, Series 2001A,

5/11 at 100.00

AAA

8,396,423

   5.000%, 5/15/21 - MBIA Insured

 

Port of Houston Authority of Harris County, Texas, General Obligation Port Improvement Bonds,

Series 2001B:

3,205

   5.500%, 10/01/18 (Alternative Minimum Tax) - FGIC Insured

10/11 at 100.00

AAA

3,421,594

3,375

   5.500%, 10/01/19 (Alternative Minimum Tax) - FGIC Insured

10/11 at 100.00

AAA

3,583,879

 

7,205

San Antonio, Texas, Airport System Improvement Revenue Bonds, Series 2001, 5.375%, 7/01/15

7/11 at 101.00

AAA

7,667,705

   (Alternative Minimum Tax) - FGIC Insured

 

Tarrant County, Texas, Health Facilities Development Corporation Texas Health Resources System

Revenue Bonds, Series 1997A:

2,900

   5.250%, 2/15/22 - MBIA Insured

2/08 at 102.00

AAA

2,987,522

6,500

   5.000%, 2/15/26 - MBIA Insured

2/08 at 101.00

AAA

6,482,840

 

9,670

Texas Department of Housing and Community Affairs, Single Family Mortgage Revenue Bonds, Series

9/06 at 102.00

AAA

9,968,996

   1996D, 6.250%, 9/01/28 (Alternative Minimum Tax) - MBIA Insured

 

1,910

Waco, Texas, Combined Tax and Revenue Certificates of Obligation, Series 2004, 5.000%, 2/01/21 -

2/14 at 100.00

AAA

1,971,999

   MBIA Insured

 

1,840

Ysleta Independent School District, Texas, Public Facility Corporation, Lease Revenue Refunding

11/09 at 100.00

AAA

1,902,762

   Bonds, Series 2001, 5.375%, 11/15/24 - AMBAC Insured


Utah - 1.3%

 

2,000

Clearfield City, Utah, Sales Tax Revenue Bonds, Series 2003, 5.000%, 7/01/28 - FGIC Insured

7/13 at 100.00

AAA

2,006,060

 

10,000

Intermountain Power Agency, Utah, Power Supply Revenue Refunding Bonds, Series 2003A, 5.000%,

7/13 at 100.00

AAA

10,585,900

   7/01/16 - FSA Insured

 

4,155

Utah Housing Finance Agency, Multifamily Housing Refunding Bonds, FHA-Insured Mortgage Loans,

1/05 at 100.00

AA

4,160,900

   Issue 1992A, 7.400%, 7/01/24

 

120

Utah Housing Finance Agency, Single Family Mortgage Bonds, Series 1994D, 6.750%, 1/01/27

1/05 at 102.00

Aaa

120,685

   (Alternative Minimum Tax)


Virginia - 0.9%

 

1,035

Loudoun County Industrial Development Authority, Virginia, Public Safety Facilities Lease Revenue

6/14 at 100.00

AAA

1,106,933

   Bonds, Series 2003A, 5.250%, 12/15/20 - FSA Insured

 

10,000

Virginia Housing Development Authority, Commonwealth Mortgage Bonds, Series 2001H-1, 5.375%,

7/11 at 100.00

AAA

10,019,600

   7/01/36 - MBIA Insured


Washington - 1.4%

 

4,000

Lake Washington School District No. 414, King County, Washington, General Obligation Bonds, Series

12/14 at 100.00

AAA

4,288,400

   2004, 5.000%, 12/01/15 - FSA Insured

 

3,195

Kitsap County, Washington, Limited Tax General Obligation Bonds, Series 2000, 5.500%, 7/01/25 -

7/10 at 100.00

AAA

3,365,741

   AMBAC Insured

 

4,250

Snohomish County Public Utility District 1, Washington, Generation System Revenue Bonds, Series

1/05 at 100.00

AAA

5,104,377

   1989, 6.650%, 1/01/16 - FGIC Insured

 

4,345

Washington State Public Power Supply System, Nuclear Project 1 Revenue Refunding Bonds, Series

7/07 at 102.00

AAA

4,585,583

   1997A, 5.125%, 7/01/17 - AMBAC Insured


West Virginia - 0.8%

 

10,000

Harrison County Commission, West Virginia, Solid Waste Disposal Revenue Bonds, West Penn Power

11/04 at 101.00

AAA

10,132,900

   Company, Harrison Station Project, Series 1993B, 6.300%, 5/01/23 (Alternative Minimum Tax) -

   MBIA Insured


Wisconsin - 4.0%

 

680

Wisconsin Housing and Economic Development Authority, Housing Revenue Bonds, Series 1992A, 6.850%,

1/05 at 100.00

AAA

681,088

   11/01/12 - MBIA Insured

 

2,890

Wisconsin, General Obligation Bonds, Series 2004-3, 5.250%, 5/01/20 - FGIC Insured

5/14 at 100.00

AAA

3,098,311

 

10,945

Wisconsin, General Obligation Bonds, Series 2004-4, 5.000%, 5/01/20 - MBIA Insured

5/14 at 100.00

AAA

11,420,775

 

15,000

Wisconsin Health and Educational Facilities Authority, Revenue Bonds, Marshfield Clinic Project,

2/07 at 102.00

AAA

15,708,750

   Series 1997, 5.750%, 2/15/27 - MBIA Insured

 

18,000

Wisconsin Health and Educational Facilities Authority, Revenue Bonds, Aurora Health Care Inc.,

8/07 at 102.00

AAA

19,006,200

   Series 1997, 5.250%, 8/15/17 - MBIA Insured


Wyoming - 0.3%

 

3,125

Wyoming Community Development Authority, Housing Revenue Bonds, Series 1997-6, 5.600%, 6/01/29 -

12/07 at 101.50

AAA

3,200,183

   AMBAC Insured


$

1,996,567

Total Long-Term Investments (cost $1,787,407,845) - 150.7%

1,900,506,159



Short-Term Investments - 0.9%

 

4,000

Massachusetts Development Finance Authority, Revenue Bonds, Variable Rate Demand Obligations,

A-1+

4,000,000

   Boston University, Series 2002R-2, 1.070%, 10/01/42 - XLCA Insured†

 

2,000

New York City, New York, General Obligation Bonds, Variable Rate Demand Obligations, Series

A-1

2,000,000

   2002A-7, 1.040%, 11/01/24 - AMBAC Insured†

 

5,000

New York City Municipal Water Finance Authority, New York, Water and Sewerage System Revenue Bonds,

A-1+

5,000,000

   Variable Rate Demand Obligations, Fiscal Series 1994G, 1.080%, 6/15/24 - FGIC Insured†


$

11,000

Total Short-Term Investments (cost $11,000,000)

11,000,000



Total Investments (cost $1,798,407,845) - 151.6%

1,911,506,159


Other Assets Less Liabilities - 2.3%

29,549,499


Preferred Shares, at Liquidation Value - (53.9)%

(680,000,000)


Net Assets Applicable to Common Shares - 100%

1,261,055,658


  

All of the bonds in the portfolio, excluding temporary investments in short-term municipal securities, are

either covered by Original Issue Insurance, Secondary Market Insurance or Portfolio Insurance, or are

backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities,

any of which ensure the timely payment of principal and interest.

(1)  

All percentages shown in the Portfolio of Investments are based on net assets applicable to Common

shares.

*  

Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption.

There may be other call provisions at varying prices at later dates.

**  

Ratings: Using the higher of Standard & Poor's or Moody's rating.

(WI)  

Security purchased on a when-issued basis.

†  

Security has a maturity of more than one year, but has variable rate and demand features which qualify

it as a short-term security. The rate disclosed is that currently in effect. This rate changes periodically

based on market conditions or a specified market index.

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial

statement and federal income tax purposes are primarily due to timing differences in recognizing income

on taxable market discount securities and timing differences in recognizing certain gains and losses on

security transactions.

At July 31, 2004, the cost of investments were $1,797,271,875.

Gross unrealized appreciation and gross unrealized depreciation of investments at July 31, 2004 were as follows:


Gross unrealized:

   Appreciation

$   116,442,458

   Depreciation

(2,729,349)


Net unrealized appreciation of investments

$   113,713,109


Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rules 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934, as amended (the "Exchange Act")(17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)), exactly as set forth below: EX-99 CERT Attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Insured Municipal Opportunity Fund, Inc.        

By (Signature and Title)*          /s/ Jessica R. Droeger--Vice President and Secretary        

Date         09/29/04        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*         /s/ Gifford R. Zimmerman--Chief Administrative Officer (Principal Executive Officer)        

Date         09/29/04        

By (Signature and Title)*         /s/ Stephen D. Foy--Vice President and Controller (Principal Financial Officer)        

Date         09/29/04        

* Print the name and title of each signing officer under his or her signature.