VIENNA OPEC oil ministers left the market guessing about whether they might raise output in the second half of this year after deciding against a hike before June, saying it would depend on demand.

All eyes will be on Russia this week for an expected decision from Moscow on whether to bow to pressure from OPEC to extend until June an oil export cut it reluctantly introduced at the start of this year.

Energy chiefs from the Organization of Petroleum Exporting Countries (OPEC) formally agreed as expected here late Friday to leave crude oil output levels unchanged in the second quarter, extending swingeing export cuts that have helped haul prices back from a post-September 11 slump.

They agreed to meet again on June 26 to review the situation, saying it was impossible to know yet whether they would need to start pumping more oil later this year.

OPEC President Rilwanu Lukman said that the 11-member oil producer group had to keep its options open. "By the time June comes, we will see what the market is calling for," he said.

"If the market is calling for more (oil), we will supply it," he told AFP after the meeting.

Lukman said he was "cautiously optimistic" about oil prices, which slumped to under $17 a barrel after September 11 but which have surged back up in recent weeks.

"There is every reason to believe that prices will continue to strengthen in the coming weeks and months, as they approach longer-term sustainable and widely acceptable levels," he said.

"We are cautiously optimistic about the near-term outlook for the international oil market," he added.

Analysts agreed that it was too early for opec ministers to tell whether the market would need more supply by the time they met again in June.

Much of the recent froth on the oil market has been caused by worries about possible disruption to Middle East supplies because of rising U.S.-Iraq tensions and a wave of Israeli-Palestinian bloodshed, they added.

Ministers were however quick to assure consumers that they would act to stabilize the market if there was a dearth of oil as a result of any U.S.-led military action against Iraq.

According to Mehdi Varzi, an analyst at Dresdner Kleinwort Wasserstein, OPEC members appeared happy with the current oil price, which has rebounded above $24 in London and New York.

Varzi said that OPEC's goal at the latest gathering had just been to stabilize prices in the second quarter.

"They are not going to give any indication for the second half because there is too much uncertainty," he told AFP.

But Leo Drollas, an oil expert at the London-based center for global energy studies, warned that OPEC's decision not to raise output now could backfire.

If oil prices keep rising, that would deal a blow to the fragile global economy, which would in turn crimp demand growth and hurt prices, he said.

"They are playing a bit with fire," he told AFP.

"If prices go up high in the third quarter and into the fourth that will knock the recovery on the head," he added.