Oil prices slipped as the dollar rose against other major currencies.
Benchmark crude for May delivery fell eight US cents to settle at $US80.53 a barrel on the New York Mercantile Exchange.
Crude, which is priced in dollars, tends to fall in price as the greenback rises and makes oil barrels tougher to buy with foreign currency.
Oil prices initially gained after the Labor Department reported that claims for jobless benefits dropped more than expected last week, before falling back later in the day.
Meanwhile, the futures contract for natural gas tumbled three per cent after the government reported that supplies grew for the first time this year, adding to already bloated reserves.
The US had been burning large volumes of natural gas to heat homes and run power generators this winter as heavy snowstorms blanketed parts of the country. But the drawdown wasn't enough to erase huge surpluses built up during the past few years.
The Energy Information Administration said that at 1.63 trillion cubic feet, natural gas levels are eight per cent higher than the five-year average.
Natural gas for April delivery dropped 12.4 US cents to settle at $US3.981 per 1,000 cubic feet on the Nymex. Prices fell as low as $US3.94 earlier in the day, the lowest on record for the April contract.
In other Nymex trading in April contracts, heating oil fell less than a penny to settle at $US2.0693 a gallon, and gasoline lost less than a penny to settle at $US2.2177 a gallon.
In London, Brent crude slid a penny to settle at $US79.61 on the ICE futures exchange.
April gold futures added $US4.10 to settle at $US1,092.90 per fine ounce.
May silver rose 10 US cents to settle at $US16.741, while May copper gained 3.5 US cents to $US3.3805 per pound.
