Oil prices eased further on Thursday, pressured by bulging U.S. crude stockpiles and expectations that a strike in Nigeria would not slow shipments from the eighth largest oil exporter.

Producer group OPEC said the healthy oil supply situation has bolstered its case for keeping output limits in place, and underscored that tight stocks of gasoline in the United States are due to a lack of refining capacity, not crude.

There is a lot of oil on the market, the stocks are very high, OPEC Secretary-General Abdullah al-Badri said on Thursday. If we add more oil, it would not go to the refineries -- it would go to the stocks.

London Brent crude, seen as the best indication of world oil prices, fell 23 cents to $70.19 a barrel by 1830 GMT, adding to Wednesday's losses of $1.42. U.S. crude slipped 26 cents to $68.60 a barrel.

The market has been under pressure since a U.S. government report on Wednesday showed crude inventories rose last week to their highest level in nine years due to strong imports and low demand from U.S. refineries hobbled by mechanical problems.

But U.S. supplies of refined fuels, like gasoline and heating oil, remain below normal for this time of year, according to the report from the Energy Information Administration.

Also weighing on prices were expectations that a nationwide strike in Nigeria would spare oil shipments, and could end soon amid talks between the government and the unions.

There is talk about the possible meeting between the Nigerian government and the strikers, said Mark Waggoner, president of Excel Futures.

Oil supplies from Africa's top oil exporter were as yet unaffected on the second day of the general strike that has paralyzed most economic activity in Nigeria.

But about 25 percent of Nigeria's oil output is already shut because of militant attacks on the country's oil facilities.

Nigerian troops on Thursday dislodged militants occupying an oil facility operated by Italy's Eni, where the company had said 27 people including 11 soldiers had been held since the facility was overrun on Sunday.

Meanwhile, the Organization of the Petroleum Exporting Countries (OPEC) played down any expectations the exporter group could boost output, saying such a move was unnecessary and would only add to ample oil stocks in consumer nations.

As we see it now there is no shortage, OPEC Secretary-General Abdullah al-Badri told reporters ahead of a meeting with EU officials at OPEC's Vienna headquarters.

European Energy Commissioner Andris Piebalgs admitted there was no crude shortage in the market, but called on OPEC to steer away from output restrictions.

OPEC next meets in September.

(Additional reporting by Santosh Menon in London)