May 6 (Bloomberg) -- Indonesia, the only OPEC member in Southeast Asia, may leave the group as early as next year because shrinking production has made the country a net importer of oil.

``We are now studying the option,'' Energy Minister Purnomo Yusgiantoro told reporters in Jakarta today. The government may leave the Organization of Petroleum Exporting Countries in 2009 because it has paid its membership fee for this year, he said.

Indonesia has been weighing leaving the body since at least 2005 as output at aging wells declined and investment in exploration slowed. At a meeting yesterday, officials discussed withdrawing from OPEC for as long as the country's production remains below 1 million barrels of oil a day, state news agency Antara reported today, citing President Susilo Bambang Yudhoyono.

``If Indonesia leaves, it doesn't make a big difference to OPEC as it only highlights the country's declining production to the market,'' said Tony Regan, an energy consultant with Nexant Ltd. in Singapore. ``Nothing will change in terms of their imports and exports.''

OPEC members account for 40 percent of the world's oil supply.

Southeast Asia's biggest economy imports about one-third of its oil product needs because it lacks adequate refining capacity and faces falling oil output. The Indonesian government has lowered its oil sales estimate for 2008 to 927,000 barrels a day from 950,000 barrels a day last year.

Lower Output

Indonesia's crude output likely fell to 859,853 barrels a day in April from 867,516 barrels a day in March, oil and gas regulator BPMigas said on April 29.

The country plans to sell 7 million barrels of oil, or half of its stockpile, this year to increase government revenue as crude prices reached a record, Purnomo said on April 29. This may add $665 million to state coffers, on the assumption that Indonesia's oil price averages $95 a barrel this year, as stated in the budget.

Crude oil rose to a record $120.68 a barrel in New York on speculation demand will rise during the peak summer driving season in the U.S. and ahead of the Beijing Olympics.

Oil for June delivery was at $120.56 a barrel at 4:01 p.m. in Singapore in after-hours trading on the New York Mercantile Exchange.

To contact the reporters on this story: Berni Moestafa in Jakarta at bmoestafa@bloomberg.net; Naila Firdausi in Jakarta at nfirdausi@bloomberg.net.

Last Updated: May 6, 2008 04:08 EDT