SAO PAULO (Reuters) - Brazilian mining giant Vale is in advanced talks to sell a majority stake in a renewable energy unit and a solar plant to U.S.-based investment firm Global Infrastructure Partners (GIP), two people familiar with the matter said.

The deal for 70% of both Vale's Alianca Energia and the solar plant had also attracted interest from energy generators Casa dos Ventos and China Three Gorges (CTG) Brasil, which are no longer in the running, sources said.

Vale has chosen to continue negotiations exclusively with GIP, but a final contract has not been signed, sources added.

Vale said in a statement that it is seeking potential partners for Alianca, but no final decision has been reached and no binding agreement has been signed.

GIP declined to comment.

One of the sources said GIP could pay some 5-6 billion reais ($870 million to $1.04 billion) for 70% of Alianca and the solar plant. Alianca runs a portfolio of hydroelectric power plants and wind farms, with total installed capacity of nearly 1,300 megawatts.

Brazilian news website Faria Lima Journal first reported on Thursday that talks between Vale and GIP were advancing.

Vale became sole owner of Alianca last year, when it paid 2.7 billion reais ($470 million) for the 45% stake held by power firm Cemig, with whom it launched the venture in 2013.

($1 = 5.77 reais)