Oil eased to around $71 a barrel on Tuesday as investors weighed ample fuel stocks in top consumer the United States and the potential for higher Nigerian crude exports.

London Brent crude, now a better gauge of the global market than U.S. oil, slipped 47 cents to $70.89 a barrel by 1307 GMT, after gaining 18 cents on Monday. U.S. crude dipped 30 cents to

$68.88.

U.S. crude inventories, already at a nine-year high, are expected to have climbed a further 900,000 barrels last week, according to a Reuters poll. Stocks of gasoline are expected to rise by 1.1 million barrels.

There are some bearish factors in the market now but I don't know how long they will last as the market seems to refuse to go down, said Tony Nunan of Japan's Mitusbishi Corp.

For now, prices are pressured by the end of an output-threatening strike in Nigeria and Royal Dutch Shell's plans to restart exports next month from the country's Forcados terminal -- using oil that is in storage.

Shipments from the facility have been stopped for more than a year by militant attacks. But it is likely to be some time before production resumes from the Forcados oilfield, a company official said on Tuesday.

About 711,000 barrels per day of output in Nigeria, Africa's largest exporter, has been closed due to militant attacks.

The threat of still further supply disruptions in the OPEC member helped push Brent to a 10-month high of $72.25 last week.

The rising price of oil has prompted consumer governments to urge OPEC to boost supplies and ease prices that have risen from near $50 in January.

But OPEC's president, Mohammed al-Hamli, reiterated on Tuesday that the 12-member group was keeping world markets well supplied and stockpiles were high.

OPEC producers, excluding Iraq and Angola, are set to pump slightly more oil in June at 26.8 million barrels per day because of higher shipments from some members including Iran and Algeria, said Conrad Gerber, head of consultancy Petrologistics.