QUITO (Reuters) - A pair of international oil firms are set to reject new contracts offered by Ecuador's government as part of the OPEC member's bid to increase state revenue from the sector, President Rafael Correa said on Saturday.

Tuesday is the deadline for executives to sign new deals that would throw out profit-sharing arrangements in favor of flat-fee service contracts. The government says companies that do not sign the new pacts would have to leave the country.

"We have lost a pair of companies, what a shame," Correa said, according to state media.

The leftist leader did not mention any companies by name, but several firms, such as Brazil's Petrobras <PETR4.SA> <PBR.N> and two companies controlled by China's top oil and gas company, CNPC, have balked at the terms being offered.

"We will sign contracts with the grand majority of businesses that accept the new contracts, and maybe a pair of companies that want to leave the country will have their concessions terminated," he was quoted as saying on the state's El Ciudadano news site.

Wilson Pastor, Ecuador's minister for oil policy, said on Friday he hoped the differences could be worked out in time for the deals to be signed on Tuesday.

Other oil companies involved in the negotiations include Spain's Repsol-YPF <REP.MC> and Italy's Eni <ENI.MI>.

The new contracts are key to Correa's agenda as he fights to increase state revenue from energy and mining after a 2008 debt default restricted Ecuador's access to international capital markets.

Chinese companies Andes Petroleum and PetroOriental, both controlled by CNPC, have threatened to seek arbitration, saying the talks have been "marked by a lack of transparency -- in terms of take it or leave it, confiscatory measures and pressure to accept conditions.

(Reporting by Santiago Silva; Editing by Peter Cooney)