X0306 4 2014-02-28 0 0001419242 ATLANTIC POWER CORP AT 0001487813 Welch Barry Edward C/O ATLANTIC POWER CORPORATION ONE FEDERAL STREET, 30TH FLOOR BOSTON MA 02110 1 1 0 0 Chief Executive Officer Common Shares 2014-02-28 4 M 0 5973 A 345014 D Common shares 2014-02-28 4 F 0 1991 2.64 D 345014 D Common shares 2014-02-28 4 M 0 18696 A 345014 D Common shares 2014-02-28 4 F 0 6232 2.64 D 345014 D Notional shares 2014-02-28 4 M 0 5973 A Common share 5973 24669 D Notional shares 2014-02-28 4 M 0 18696 A Common share 18696 24669 D the reporting person acquired shares pursuant to the vesting (disclosed on Table II) of notional shares awarded in 2012 in respect of the 2011 performance year (the "Supplemental Grant"). Two thirds of the vested notional shares were settled in common shares and one third were settled in cash, which was deposited into the reporting persons applicable payroll tax withholding account. the reporting person acquired shares pursuant to the vesting (disclosed on Table II) of notional shares awarded in 2012 in respect of the 2011 performance year (the "Annual Grant"). Two thirds of the vested notional shares were settled in common shares and one third were settled in cash, which was deposited into the reporting persons applicable payroll tax withholding account. The reporting person vested in respect of one-third of the notional shares granted in 2012 with respect to the 2011 performance period (including additional notional shares accrued pursuant to dividend equivalent rights) (the "Supplemental Grant"). The reporting person vested in respect of one-third of the notional shares granted in 2012 with respect to the 2011 performance period (including additional notional shares accrued pursuant to dividend equivalent rights) (the "Annual Grant"). The amount of securities beneficially owned following the reported transactions reflect those holdings as of the date of this Form. 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. /s/Barry E. Welch 2014-03-04