The usual seasonal pickup in oil demand as refiners ramp up for the summer driving season may be too small this year to overcome doubts about weakening of oil demand growth that have dragged prices lower this week, according to industry experts.

Lack of demand from European refiners for Saudi Arabian crude, which prompted the world's largest exporter to cut 500,000 barrels a day of oil output late last month, may also persist into summer. This should ease concerns about spare oil production capacity that have played a big part in pushing up prices in recent months, industry analysts said.

These two factors reinforce the bearish sentiment that this week reversed a steady climb in the oil price, they said.

The recent oil price rally was started by stronger demand in the recovering world economy, but it was the loss of 1.3 million barrels a day of Libyan oil production because of the civil war that propelled prices to the two-and-a-half year high of over $127 a barrel for benchmark Brent crude last week.

The cut in Libyan exports, around 70% of which went to European refiners, did not cause any immediate shortages and members of the Organization of Petroleum Exporting Countries quickly promised to fill any supply gaps that did emerge from the oil production capacity they hold in reserve.
Saudi Arabia pledged to release an extra 500,000 to 600,000 barrels a day onto the market.

Nevertheless, prices have climbed steadily higher, driven in large part by fears that if political unrest spread to other oil producers,
Saudi Arabia 's newly diminished spare capacity would fall short.

However, this week after Saudi officials revealed that in the second half of March they had shut down almost all of this extra production due to lack of interest from buyers. The sharp fall in prices that followed this, by as much as $5 a barrel at one point Tuesday, was compounded by reports from the International Energy Agency, OPEC and Goldman Sachs warning that high oil prices may already be biting into demand growth.

Thursday, Brent crude remained around $5 below its recent peak at just over $122 a barrel.

Yet despite these bearish signals, the IEA warned that oil markets could soon tighten again. The lack of demand for Saudi crude in March was due to temporary maintenance at refineries and the immediate impact of the Japanese earthquake and tsunami, which also shut down many refineries, it said. The Saudi supply cut, "overlooks a crude demand trend which potentially sees throughputs rise from March lows and add 3 million barrels a day by July," as refineries restart, it said.

However, others caution that the refining rebound is likely to be weak this year and among those companies that will be looking for extra oil supplies, there is little demand for what
Saudi Arabia is offering.

"Refining margins have been terrible, particularly for those processing light, sweet crude," said Jonathan Leitch, a senior analyst at consultancy Wood Mackenzie. "Refiners have either reduced output or are shutting down altogether."

Leitch said he is definitely not expecting a summer rebound in demand from refiners as large as 3 million barrels a day. "In April and May we would be looking for runs to remain fairly tame. Maybe by June or July they could pick up because of the
U.S. driving season," he said. At most, refining throughput could grow by 1.5 million barrels a day in OECD countries, he said.

Most European refiners were reluctant to comment on how much crude they intend to process in the coming months, but there was little sign they were relying on the Saudis.

"We have always said that the Saudi crude on offer wouldn't do as a substitute for the Libyan one," said a spokeswoman for Italian refiner Saras SpA (SRS.MI).

Saudi efforts to create a special blend of crude similar to the lost Libyan supplies haven't satisfied European refiners, who were turned off by the higher sulfur content of the oil, said Leitch. The price at which Saudi offered the oil was also too high, said the IEA.

Saras, which can process 300,000 barrels a day of crude at its refinery on the
island of Sardinia , has mainly targeted crude from the Caspian area to replace Libyan supplies, she said.

A spokesman for Spanish oil company Repsol YPF SA (REP.MC) said it bought oil cargoes on the spot market to offset the loss of Libyan crude, rather than turn to the Saudis.

Greece 's largest refiner Hellenic Petroleum SA (ELPE.AT) is still getting less than 6.5% of its crude from Saudi Arabia , said Evangelos Stranis, director of corporate affairs at the company.

To be sure, with no end in sight to the Libyan conflict it is unclear how long refiners will be able to continue with ad-hoc arrangements to find alternative oil supplies on the open market.

Competition for light, sweet crude produced in
West Africa or the Caspian region could drive the premiums for the grades higher relative to other varieties, said Leitch. The IEA noted that the rise in premiums for African crudes, "has prompted a number of Asian refiners to pick up extra Saudi grades for May." However, Leitch said he did not think that this trend would be powerful enough to drive the price of the global crude benchmarks higher.

Broader issues, notably the debate over whether oil prices are indeed high enough to slow the world economy, look set to dominate the market for the time being.