FirstEnergy and Allegheny Energy say they have filed an application with the Federal Energy Regulatory Commission seeking approval of their proposed merger.

The companies said they will seek state regulatory approval in Pennsylvania, West Virginia and Maryland this month and in Virginia later in the year. The joint statement said the merger is expected to close in the first half of next year.

FirstEnergy announced in February that it was buying Allegheny Energy in a $4.7 billion stock deal that would result in a company made up of 10 utilities serving 6.1 million customers from Ohio to New Jersey.

Several Allegheny Energy shareholders have filed suit seeking to block the takeover, saying it undervalues the stock they own.