MILAN, Dec 21 (Reuters) - Energy group ERG ERG.MI will enter the U.S. renewable energy market after it signed a deal for a strategic partnership with Apex Clean Energy Holdings, the Italian firm said on Thursday.

The deal involves setting up a U.S.-based holding company that will encompass a wind farm and a solar plant, both set up recently, with a total capacity of 317 megawatts.

ERG will buy 75% of the new holding company for $270 million, while Apex will hold the remaining 25%. The deal is expected to be completed by the first half of next year.

The plants, located in the states of Iowa and Illinois respectively, are estimated to generate around 1 terawatt hours (TWh), the firm said in a statement.

The two assets benefit from tax equity investments with market-leading counterparts and will be debt-free at closing, ERG said, adding it expects a steady revenue stream from the projects via long-term power purchase agreements.

Rothschild & Co acted as financial advisor to the transaction.

(Reporting by Federico Maccioni, editing by Gianluca Semeraro and Janane Venkatraman)

((Federico.maccioni@thomsonreuters.com; +39 3420768883;))