WARSAW, April 28 (Reuters) - U.S. firms Westinghouse

Electric and Bechtel signed a contract on Monday with Poland's

state-owned Polskie Elektrownie Jadrowe (PEJ) to continue

designing the country's first nuclear power plant, after an

initial agreement expired at the end of March.

Poland is seeking to reduce its reliance on coal and chose

Westinghouse in 2022 to build the plant on the Baltic Sea coast.

Warsaw estimates the project's cost at 192 billion zloty ($51

billion).

"I believe it's the start of a long-term nuclear

cooperation between the United States and Poland that will

involve building future reactors, both here in Poland and with

other nations across Europe," U.S. Energy Secretary Chris Wright

said during the signing ceremony.

Polish Prime Minister Donald Tusk said that he and Wright

discussed the future of small nuclear reactors and cooperation

on liquefied natural gas (LNG). Poland relies on U.S. LNG to

diversify its gas supplies.

PEJ still needs to negotiate an engineering, procurement and

construction (EPC) contract with the builder but that requires

European Commission approval for public aid worth 60 billion

zloty ($16 billion) that the project is set to benefit from.

Poland aims to get the EU nod for the project by the end of

the year to start the construction of the first unit of the

plant in 2028 and complete it in 2036, four years later than

initially planned.

The plant, which already has backing from U.S. and Canadian

financial institutions is due to be fully operational by 2040.

($1 = 3.7670 zlotys)

(Reporting by Marek Strzelecki, Anna Koper; Editing by Emelia

Sithole-Matarise)