CPFL Energia SA, Brazil's largest power distributor, said on Friday that the world's largest utility, China's State Grid International Development Ltd, will buy a controlling stake in the company for 5.85 billion reais ($1.8 billion).

Camargo Correa SA, a privately held Brazilian engineering, real estate, textile and shipbuilding company, is selling the 23 percent stake, CPFL said in a securities filing.

State Grid will pay 25 reais for each of Camargo's 234 million CPFL shares.

Other shareholders have the option to outbid State Grid or sell their stakes to the Chinese company on equal terms, which could largely increase the final size of the deal.

State Grid has said that it plans to expand in Brazil beyond the power transmission assets it already manages. CPFL has a large portfolio of power generation installations.

The deal is subject to approval by Brazilian antitrust regulators, Camargo Correa said in a letter included in the filing.