FirstEnergy and Allegheny Energy have filed an application with the Federal Energy Regulatory Commission (FERC) for approval of their proposed merger.

The application provides additional detail and analysis related to competition in wholesale electric power markets, FERC jurisdictional rates, and state and federal regulation of both companies and their subsidiaries. Under the Federal Power Act, the FERC has 180 days to rule on a merger application.

The companies plan to make filings for state regulatory approval in Pennsylvania, West Virginia and Maryland this month, and in Virginia later in the second quarter.

The merger is expected to close in the first half of 2011, subject to customary closing conditions, including shareholder and regulatory approvals, as outlined in the preliminary S-4 registration statement, which was filed in March.

Allegheny Energy, an investor-owned utility, owns and operates generating facilities and delivers electric service to over 1.5 million customers in Pennsylvania, West Virginia, Maryland and Virginia.

FirstEnergy is a diversified energy company headquartered in Akron, Ohio. Its subsidiaries and affiliates are involved in the generation, transmission and distribution of electricity, as well as energy management and other energy-related services.