Crude oil prices settled slightly higher Tuesday as traders speculated that supply would be tight late in the year.

On the New York Mercantile Exchange, crude oil futures for June delivery added 4 cents to end at 52.07 dollars a barrel. Meanwhile, on London's International Petroleum Exchange the June Brent crude- oil futures contract rose 17 cents to finish at 51.46 dollars per barrel.

On Tuesday, a major official from the Organization Petroleum Exporting Countries (OPEC) said the oil cartel might not be able to produce more to meet needs for the remainder of 2005. "OPEC is at its highest production in history. I am concerned about that. If we reach the full capacity now, we will tighten in the fourth quarter," Dow Jones Newswires quoted Abdullah Hamad al-Attiyah, Qatar's oil minister, as saying.

OPEC pumped about 40 percent of world oil and raised production targets to about 30 million barrels daily this year. Analysts concerned that OPEC was producing at full pace, with no spare capacity in the event of a sudden rise in global demand.

Brokers were surprised that the price of oil had remained as high as it had, noting US inventories had been increasing for nearly 12 weeks. "There's a little bit of a disconnect between the (supply-demand) fundamentals and the (price) trend," said a broker in New York. "Prices should retreat in the next month or so into the mid-40 dollars."

On Wednesday, two reports would have definite effects on the market. The US Department of Energy would release its weekly petroleum inventory data, while International Energy Agency would issue its monthly oil report about global demand.