X0303 4/A 2010-09-28 2010-09-30 0 0000003673 ALLEGHENY ENERGY, INC AYE 0001377787 Feinberg David Matthew C/O ALLEGHENY ENERGY, INC 800 CABIN HILL DRIVE GREENSBURG PA 15601 0 1 0 0 VP & General Counsel Common Stock, $1.25 par value 2010-09-28 4 M 0 15160 A 31190 D Common Stock, $1.25 par value 2010-09-28 4 F 0 8287 23.115 D 22903 D Common Stock, $1.25 par value 549.3293 I ESOSP Represents shares of the Issuer's common stock, par value $1.25 per share (the "Common Stock"), issuable to Mr. Feinberg in connection with the vesting of previously-granted restricted stock awards. Granted under Allegheny Energy, Inc.'s 2008 Long-Term Incentive Plan. Shares of the Issuer's Common Stock withheld as payment for minimum required federal, state and local tax withholdings with respect to the vesting of the 15,160 shares reported on Table I, as well as in connection with the vesting of a portion of the restricted stock award previously reported by Mr. Feinberg on his Form 4 dated March 3, 2009. Calculated based on the average of the high and low sale prices for a share of the Common Stock on the New York Stock Exchange on September 14, 2010. Held through the Allegheny Energy, Inc. Employee Stock Ownership and Savings Plan. Amanda J. Skov Attorney-in-Fact 2010-12-08