The builder and operator of the world's largest dam, China Three Gorges Corporation, has agreed to acquire Duke Energy's 2,090-megawatt business in Brazil for $1.2 billion.

The transaction is expected to be completed in the first half of 2017, said Duke Energy, the biggest U.S. power company by generation capacity.

The completion of the transaction is conditioned on approvals from Brazilian electrical energy and antitrust agencies as well as the Chinese authorities, it said.