Japan Inpex to up investment in Kashagan oilfield

TOKYO, May 14 (Reuters) - Inpex Holdings Inc (1605.T: Quote, Profile, Research), Japanese biggest oil and gas explorer, plans to increase investments in Kazakhstan's Kashagan oil field in the Caspian Sea by 25 percent or more in the business year that started in April, a company executive said on Wednesday.

"Investments have been gradually rising as planned and we expect to invest 50 billion yen ($481.9 million) to 60 billion yen ($578.2 million)," Mutsuhisa Fujii, Inpex director told reporters.

That compared with about 40 billion yen invested in the year that ended in March.

Fujii said Inpex was part of a consortium discussing the details of a deal reached in January, such as the start date of production and investment amounts, but declined to comment further.

The consortium of Italy's Eni (ENI.MI: Quote, Profile, Research), Exxon Mobil (XOM.N: Quote, Profile, Research), Royal Dutch Shell (RDSa.L: Quote, Profile, Research) and others including Inpex, is due to submit its proposals on the future of the world's biggest oil find in three decades by the end of this month.

The January deal, while calming investor confidence shaken after six months of squabbling between Kazakhstan and the oil majors, will be enforced only after the sides agree on the precise production and structural details of the project.

Under that deal, Kazakh's state-owned KazMunaiGas would double its stake in Kashagan and strip Eni of its leading role in the project, whose production start has been further delayed to the end of 2011.

The deal followed a stand-off that started in August when the Kazakh government accused its shareholders of allowing costs to spiral to $136 billion from $57 billion, and delaying the start of production from the original 2005 target.

Kazakhstan threatened this month to slap sanctions on the consortium should its operators decide to delay the start of production again.

Other shareholders in the project are Total (TOTF.PA: Quote, Profile, Research) and ConocoPhillips (COP.N: Quote, Profile, Research). (Reporting by Osamu Tsukimori)