Dubai: Chevron Corp. and BP Plc are withdrawing top executives from Kuwait after more than a decade of negotiations failed to gain access to the world's fourth- largest crude oil reserves.

Hani Iskander, the Chevron Kuwait president, may leave next month after failing to reach an accord to boost output, according to two Kuwait-based officials who declined to be identified because the decision isn't final. BP's vice-president for Middle East exploration and production, Tim Marchant, is also departing as talks to invest in the country slow.

Kuwait risks missing its target of almost doubling oil production by 2020 from 2.1 million barrels a day now as parliamentary opposition blocks the country's biggest expansion efforts. The delay hobbles international oil companies that already face restrictions tapping reserves in Saudi Arabia, Iran and Iraq, the three largest producers of the Organisation of Petroleum Exporting Countries (Opec).

"Kuwait won't reach its four million barrel-a-day target without the help of established oil companies, who deal with challenging oil fields and can impose an efficient investment programme," said Raja Kiwan, a Dubai-based analyst at energy consultant PFC Energy. "The bulk of its production comes from fairly mature fields, so incremental output will come from difficult reserves in the northern fields and heavy oil."

BP's new general manager in Kuwait will be Nouf Al Abdul Razzaq, the company's former communications and external affairs manager in the country. "The office has downsized but our commitment to Kuwait is still there," she said. BP engineers moved out in 2008 after a contract to help the state oil company with management strategies ended.

The Kuwait Investment Authority, with a 1.8 per cent stake, is the third-largest shareholder in London-based BP.

Chevron, the second-largest US oil company, is "going through a normal demobilisation of staff" after a technical agreement with Kuwait Oil Co. expired in August, spokeswoman Margaret Cooper said by e-mail.