Jakarta – Indonesia's crude oil output is expected to fall by an average 100,000 barrels per day (bpd) next year due to security disruptions in its fields, a senior mines and energy ministry official said on Friday.

Indonesia's vital oil and gas industry has been hit by a series of disputes in the past year in the wake of new autonomy laws introduced on January 1, which have given regions more fiscal and administrative powers.

The country's biggest producer, PT Caltex Pacific Indonesia, has been one of the hardest hit by worker disputes and protests at its Riau operations on the island of Sumatra.

"It [the expected fall in 2002 output] is because some production sharing partners, including big ones like Caltex ... have failed to maintain production this year because of rampant security disruptions in their areas," official Kardaya Warnika told reporters. "Some other companies have cut investment for production next year and many have cancelled investment for expansion," he added.

Caltex – jointly owned by Chevron Corp and Texaco Inc – said on Tuesday output had fallen to 660,000 bpd, from a forecast 705,000 bpd, due to a range of disruptions. Caltex accounts for about half the crude oil output of Indonesia, Asia's only OPEC member.

Indonesia's crude oil production slipped to 1.23 million barrels per day (bpd) in July from 1.24 million in June, according to industry sources, partly because of the reduced output from the Caltex oil fields. Earlier this month the oil giant said it expected to post revenue losses of around $400 million this year because of the disputes. One of its most high profile rows has been at the Coastal Plain Pekanbaru (CPP) field in Riau.

Jakarta recently extended the CPP contract, which expires this month, to allow more time for preparations before it was handed to the government.

Riau has been haggling with Jakarta for months over the field and is demanding a 70 percent stake. But Jakarta has said state oil firm Pertamina would get 85 percent and the local government 15 percent.

Normal CPP output is 70,000 bpd but current production is around 50,000 bpd.

Another producer, Exxon Mobil Indonesia, was forced to close its vital gas fields in Sumatra in March due to security concerns in the rebellious Aceh province. Some of the fields were re-opened last month, but production is still below capacity and operations are on a day-to-day basis.