Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Ronan Terrence
  2. Issuer Name and Ticker or Trading Symbol
ATLANTIC POWER CORP [AT]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Executive Vice President-CFO
(Last)
(First)
(Middle)
C/O ATLANTIC POWER CORPORATION, ONE FEDERAL ST., FLOOR 30
3. Date of Earliest Transaction (Month/Day/Year)
02/28/2013
(Street)

BOSTON, MA 02110
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Shares (1) 02/28/2013   M   3,120 A $ 10.33 3,413 (5) D  
Common Shares (1) 02/28/2013   F   1,040 D $ 10.33 3,413 (5) D  
Common Shares (2) 04/11/2013   M   2,000 A $ 4.85 3,413 (5) D  
Common Shares (2) 04/11/2013   F   667 D $ 4.85 3,413 (5) D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Notional Shares (3) 02/28/2013   M   3,120 (3)     (3)   (3) Common Share 3,120 $ 10.33 10,240 (5) (6) D  
Notional Shares (4) 04/11/2013   A   6,000 (4)     (4)   (4) Common Share 4,000 $ 4.85 10,240 (5) (6) D  
Notional Shares (4) 04/11/2013   M   2,000 (4)     (4)   (4) Common Share 2,000 $ 4.85 10,240 (5) (6) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Ronan Terrence
C/O ATLANTIC POWER CORPORATION
ONE FEDERAL ST., FLOOR 30
BOSTON, MA 02110
      Executive Vice President-CFO  

Signatures

 /s/ Barry E. Welch, attorney-in-fact   04/15/2013
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The reporting person acquired shares pursuant to the vesting (disclosed on Table II) of notional shares awarded in 2012. Two thirds of the vested notional shares were settled in common shares and one third were settled in cash, net of applicable tax withholding.
(2) The reporting person acquired shares pursuant to the vesting (disclosed on Table II) of notional shares awarded in 2013. Two thirds of the vested notional shares were settled in common shares and one third were settled in cash, net of applicable tax withholding.
(3) The reporting person vested in respect of one-third of the notional shares granted in 2012 (including additional notional shares accrued pursuant to dividend equivalent rights).
(4) Represents a grant of notional shares pursuant to the Company's Long-Term Incentive Plan ("LTIP") in 2013 that vest ratably with respect to one-third on each of April 11, 2013 (the grant date), February 28, 2014 and February 28, 2015. Under the LTIP, each notional share represents a right to receive one-third in cash (net of any applicable withholdings) and the remainder in a fractional common share, or (at the election of the reporting person) one common share, or (at the discretion of the board of directors of the Company) cash only.
(5) The amount of securities beneficially owned following the reported transactions reflect those holdings as of the date of this Form.
(6) The total includes dividend equivalent rights accrued on the notional shares previously earned pursuant to the LTIP. Dividend equivalent rights are credited in notional shares.

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