A and three other partners in a US.4 billion Caspian Sea oil project opted to raise their stakes in the development, blocking plans by two Chinese rivals to buy the shares.

　　Exxon Mobil Corp, Total SA and ConocoPhillips also increased their interests in the Kashagan field, said Robin O'Kelly, a spokesman for BGsgroupsPlc, which is selling its share of a license in Kazakhstan's part of the Caspian Sea. Only Inpex Corp of Japan decided against buying more of the field.

　　The decision comes as oil companies face delays in talks to invest in Middle East energy projects and opportunities dwindle in other regions, such as the North Sea. The Kashagan field may hold as much as 13 billion barrels of recoverable oil, more than the reserves of Norway, the world's third-largest oil exporter.

　　BG in March agreed to sell an 8.3 percent stake in Kashagan to China Petrochemical Group, or Sinopec, and CNOOC Ltd for US million each. CNOOC and Sinopec said that BG's partners exercised rights to buy the stakes, blocking the deals.

　　Eni, Exxon Mobil, Shell and Total will each own 20.37 percent of the project following the transaction, up from 16.67 percent, said Eni, which oversees development of the field. ConocoPhillips brings its stake to 10.18 percent from 8.33 percent. Inpex retains 8.33 percent.

　　The accord covers the North Caspian Sea Pro-duction Sharing Agreement, an area of 5,600 square kilometers, which includes the Kashagan field. Partners will have to spend billions of dollars to bring the site into production, Eni has said.

　　BG will receive the same payment as agreed with the Chinese companies from its partners and expects the deal to close by the end of the year, spokesman Chris Carter said. The sale is subject to approval of the Kazakhstan government.