"If there is no delay, we are planning the first oil production for around 2011," said Te Duong Dara, director-general of the Cambodian National Petroleum Authority (CNPA), speaking at a conference of global industry experts and energy company officials in Phnom Penh.

Chevron, the most active of several firms exploring the fields, remains mum, saying only that its test wells have found that the oil and gas is "dispersed rather than located in one core field," according an earlier statement.

Government optimism has also been blunted, with Prime Minister Hun Sen warning late last year that it was "highly premature" to estimate how much oil Cambodia might hold in undersea reserves after other officials projected that the country could begin production in 2009.

Concerns have also been raised over how Cambodia -- one of the world's most corrupt countries -- would use its new-found oil and gas wealth.