Filed by FirstEnergy Corp.
Pursuant to Rule 425 under the Securities Act of 1933
and deemed filed pursuant to Rule 14a-6
of the Securities Exchange Act of 1934, as amended

Subject Company: Allegheny Energy, Inc.
Commission File No: 333-165640

The following letter was mailed on August 18, 2010 to certain FirstEnergy Corp. shareholders that have not yet voted.

		76 South Main Street Akron, Ohio 44308
Rhonda S. Ferguson
Vice President & Corporate Secretary

August 18, 2010

Dear Fellow Shareholder:

We have previously sent to you proxy material for the important special meeting of the shareholders of FirstEnergy Corp. to be held on September 14, 2010. Your Board of Directors unanimously recommends that shareholders vote FOR the proposals relating to the proposed merger with Allegheny Energy, Inc.

Since Proposals 1 and 2 require approval by holders of at least a majority of the outstanding shares, your vote is important, no matter how many or how few shares you may own. Failing to vote will have the same effect as a vote against the merger. If you have not already done so, please vote TODAY by telephone, via the Internet, or by signing, dating and returning the enclosed proxy card in the postage-paid envelope provided.

Sincerely,

Continued on reverse side.

INFORMATION CONCERNING FORWARD-LOOKING STATEMENTS

In addition to historical information, this letter may contain a number of “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. Words such as anticipate, expect, project, intend, plan, believe, and words and terms of similar substance used in connection with any discussion of future plans, actions, or events identify forward-looking statements. Forward-looking statements relating to the proposed merger include, but are not limited to: statements about the benefits of the proposed merger involving FirstEnergy and Allegheny Energy, including future financial and operating results; FirstEnergy’s and Allegheny Energy’s plans, objectives, expectations and intentions; the expected timing of completion of the transaction; and other statements relating to the merger that are not historical facts. Forward-looking statements involve estimates, expectations and projections and, as a result, are subject to risks and uncertainties. There can be no assurance that actual results will not materially differ from expectations. Important factors could cause actual results to differ materially from those indicated by such forward-looking statements. With respect to the proposed merger, these factors include, but are not limited to: risks and uncertainties relating to the ability to obtain the requisite FirstEnergy and Allegheny Energy shareholder approvals; the risk that FirstEnergy or Allegheny Energy may be unable to obtain governmental and regulatory approvals required for the merger, or required governmental and regulatory approvals may delay the merger or result in the imposition of conditions that could reduce the anticipated benefits from the merger or cause the parties to abandon the merger; the risk that a condition to closing of the merger may not be satisfied; the length of time necessary to consummate the proposed merger; the risk that the businesses will not be integrated successfully; the risk that the cost savings and any other synergies from the transaction may not be fully realized or may take longer to realize than expected; disruption from the transaction making it more difficult to maintain relationships with customers, employees or suppliers; the diversion of management time on merger-related issues; the effect of future regulatory or legislative actions on the companies; and the risk that the credit ratings of the combined company or its subsidiaries may be different from what the companies expect. These risks, as well as other risks associated with the merger, are more fully discussed in the joint proxy statement/prospectus that is included in the Registration Statement on Form S-4 (Registration No. 333-165640) that was filed by FirstEnergy with the SEC in connection with the merger. Additional risks and uncertainties are identified and discussed in FirstEnergy’s and Allegheny Energy’s reports filed with the SEC and available at the SEC’s website at www.sec.gov. Forward-looking statements included in this document speak only as of the date of this document. Neither FirstEnergy nor Allegheny Energy undertakes any obligation to update its forward-looking statements to reflect events or circumstances after the date of this document.

ADDITIONAL INFORMATION AND WHERE TO FIND IT

In connection with the proposed merger, FirstEnergy filed a Registration Statement on Form S-4 (Registration No. 333-165640) with the SEC that includes a joint proxy statement of FirstEnergy and Allegheny Energy and that also constitutes a prospectus of FirstEnergy. FirstEnergy and Allegheny Energy urge investors and shareholders to read the joint proxy statement/prospectus regarding the proposed merger, as well as other documents filed with the SEC, because they contain important information. You may obtain copies of all documents filed with the SEC regarding this proposed transaction, free of charge, at the SEC’s website (www.sec.gov). You may also obtain these documents, free of charge, from FirstEnergy’s website (www.firstenergycorp.com) under the tab “Investors” and then under the heading “Financial Information” and then under the item “SEC Filings.” You may also obtain these documents, free of charge, from Allegheny Energy’s website (www.alleghenyenergy.com) under the tab “Investors” and then under the heading “SEC Filings.”