MILAN (Reuters) -U.S. investment firm Sixth Street said on Monday it had agreed to buy 38% of Sorgenia, in a deal that values the Italian renewable energy company at 4 billion euros ($4.6 billion).

The transaction allows Spanish infrastructure fund Asterion Industrial Partners to exit Sorgenia's capital, while F2i, Italy's main infrastructure fund, retains its position as the leading shareholder in Sorgenia, with a 62% stake.

Under the agreement, F2i will transfer to Sorgenia its wind and solar power generation assets in Italy and Spain: EF Solare, Renovalia and Renovalia Tramontana.

Asterion, which held 27.6% of Sorgenia, first invested in the company in 2020 supporting its efforts to build a position as a significant player in Europe's green energy transition.

"This agreement establishes Sorgenia as one of the leading energy infrastructure platforms in Europe," Sixth Street partner Richard Sberlati said.

Sorgenia's renewable portfolio spans solar, wind, biomass, and hydroelectric plants.

The company currently operates approximately 1,700 megawatt (MW) of installed renewable capacity and is pursuing development projects totalling an additional 5,000 MW.

Rothschild & Co advised Sixth Street, together with law firm Cleary Gottlieb.

Lazard, Intesa Sanpaolo, Mediobanca acted as financial advisers to F2i and Pedersoli Gattai as legal adviser. BofA Securities, Nomura and Societe Generale each advised one of the F2i funds involved in the transaction. ($1 = 0.8636 euros)

(Reporting by Cristina Carlevaro; Editing by Valentina Za)