NEW YORK (AP)

Oil and gasolene futures fell Monday on speculation that OPEC may raise output at its meeting Tuesday.

Natural gas futures, meanwhile, jumped after a series of explosions hit natural gas pipelines owned by Mexico's state-owned oil company. While there was no word about who carried out the attacks, left-wing guerrillas have struck the country's natural gas infrastructure in the past. The U.S. imported 12.7 million cubic feet (360,000 cubic metres) of natural gas from Mexico in 2006, about 0.3 per cent of total imports that year.

Oil and gasoline futures rose off earlier lows on news of the explosions, but were still trading lower on growing expectations Saudi Arabia is working behind the scenes to persuade other Organisation of Petroleum Exporting Countries ministers to increase production.

"The market's in shock right now about the OPEC speculation," said Phil Flynn, an analyst at Alaron Trading Corp. in Chicago.

Light, sweet crude for October delivery lost 85 cents to $75.85 a barrel on the New York Mercantile Exchange after trading down more than $1 earlier. Nymex natural gas rose 8.9 cents to $5.59 per 1,000 cubic feet.

Gasolene futures fell 4.34 cents to $1.943 a gallon, and heating oil for October was off 0.91 cent at $2.1341 a gallon.

In London, October Brent crude fell 84 cents to $74.23 a barrel on the ICE Futures exchange.

At the pump, meanwhile, gas prices in the U.S. fell 0.8 cent overnight to a national average of $2.819 a gallon, reversing a recent trend of rising prices. Retail prices, which typically lag the futures market, peaked at $3.227 a gallon in late May. At the time, an unusual number of refinery outages had futures investors worried that gasolene producers would be unable to supply enough gas to meet peak summer driving demand.

But refiners boosted output over the summer, building gasolene inventories and sending prices steadily lower until late August. Analysts say the recent price increases have been driven by strong demand on the Labour Day holiday weekend and by refiners cutting back production of so-called summer gasolene, which contains fewer pollutants, in favour of cheaper-to-produce winter gasolene, which they can begin selling on Saturday.

OPEC's decision Tuesday could have a big impact on where prices go from here.

"Consulting firm PFC Energy said Saturday that it understands that 'Saudi sources have been signalling that OPEC needs to consider a production increase of 500,000 (barrels per day) to 1 million (barrels per day),"' wrote Edward Meir, an analyst at MF Global UK Ltd. in a research note.

OPEC, which produces about 40 per cent of the world's oil, has long been expected to hold production levels steady at the meeting, which is part of the reason oil and gasolene prices rose last week. Many OPEC ministers have said oil supplies are fine, blaming refiners for high gas prices.

But the Saudis are worried that high oil and gasolene prices could be pushing some countries toward recession, Flynn said. Their thinking is that reducing prices by boosting output would relieve that pressure enough to stave off recession, which would benefit oil-producing countries in the long run by keeping demand steady.

"If that's the case, it's just what the doctor ordered," Flynn said.