The terms of the agreement would involve Eldorado, which owns 21 casinos across the United States, taking a 20 percent stake in William Hill's U.S. business and could be announced as early as Wednesday, Sky News said, citing sources.

William Hill will gain distribution in Eldorado's casinos in 13 U.S. states, with an online joint venture also planned, Sky News said.

William Hill's U.S. company will also be granted restricted stock worth about 50 million pounds in the FTSE-250 bookmaker's parent company, which would vest over a period of up to five years, according to the report.

William Hill had said last month that it would push into the U.S gambling market after the U.S Supreme Court lifted a ban on sports betting in May, amid strict regulations in Britain.

The company, which has a market capitalisation of 2.14 billion pounds ($2.75 billion), said its U.S net revenue jumped 50 percent, with adjusted operating profit up 132 percent, in the six months ended June 27.

($1 = 0.7779 pound)

(Reporting by Sathvik N in Bengaluru; Editing by Tom Brown)