BERLIN/FRANKFURT (Reuters) - RWE, Germany's biggest electricity producer, is considering options for its minority stake in Amprion, one of Germany's four high-voltage power transmission networks, the company said on Tuesday, potentially paving the way for a sale.

"In view of the high capital requirements for grid expansion, we are currently examining various options and financing possibilities in relation to our Amprion investment," a spokesperson for RWE said in emailed comments.

Handelsblatt earlier reported, citing sources familiar with the matter, that RWE was considering selling its 25.1% stake in Amprion and that a sales process could possibly start this year.

The stake could be valued at 1.6 billion euros ($1.72 billion), brokerage Bernstein said in a note, adding any proceeds could be spent on a share buyback, which is something investors and analysts have pushed for.

"Selling the Amprion stake is neutral strategically but can unlock some value as the Amprion stake is usually missed in RWE's valuation," Bernstein wrote.

RWE late last year said it was open to talks about a possible sale of its Amprion stake, as efforts in Germany to restructure ownership of power networks is picking up pace.

Last year, Berlin bought a minority stake in EnBW's TransnetBW and is currently in discussions with the Dutch government to take over the German operations of grid operator TenneT.

Via state lender KfW, the German government also owns a minority stake in Elia's 50Hertz, fuelling expectations that Berlin could at some point combine its grid holdings as a way to better control critical energy infrastructure.

($1 = 0.9301 euros)

(Writing by Miranda Murray and Christoph Steitz, editing by Andrey Sychev and Susan Fenton)