Japan’s Mitsubishi Heavy Industries and the Itochu Corporation, with GDF Suez of France, will build Turkey’s second nuclear power plant at an estimated cost of $22 billion under an agreement signed Friday. The Turkish prime minister, Tayyip Erdogan, and his Japanese counterpart, Shinzo Abe, signed the deal in Ankara, Turkey. The companies will build a 4,800-megawatt nuclear power plant in Sinop, a city on the coast of the Black Sea. Turkey imports almost 97 percent of the energy it needs. Mr. Erdogan has been an advocate of its nuclear program, which aims to help reduce dependence on hydrocarbons by providing 10 percent of its electricity needs by 2023. Rosatom of Russia will build Turkey’s first nuclear power station, a $20 billion plant that will also have an installed capacity of generating 4,800 megawatts.