Oil fell more than $1 towards $75 a barrel on Tuesday after further assurances from OPEC that it would pump more crude if needed and expectations of higher U.S. fuel stockpiles.
London Brent crude, now more representative of world prices than U.S. oil, declined for a third day -- slipping $1.60 to $75.26 a barrel by 1335 GMT.
U.S. crude fell $1.40 to $73.49.
The fall today has been triggered by the comment from an Iranian oil official, said Olivier Jakob of oil consultancy Petromatrix. It is the combination of other OPEC statements at the weekend especially after OPEC had been quiet for a while.
OPEC's second biggest producer Iran said on Tuesday the exporter group would pump more crude if necessary.
In case the oil market needs it, OPEC will inject more oil into it, the official IRNA news agency quoted Javad Yarjani, head of OPEC affairs at Iran's Oil Ministry as saying.
His comment followed similar remarks from OPEC President Mohammed al-Hamli on Sunday.
Hamli, also energy minister of the United Arab Emirates said the Organization of the Petroleum Exporting Countries is
worried high oil prices may hurt the world economy.
Brent hit $78.40 last week, just off its all-time high of $78.65 last August.
The market was also weighing expected increases in inventories of refined fuel in top consumer the United States versus a forecast drop in crude oil stocks.
The strong watch will be on the gasoline stocks, said Jakob of Petromatrix.
U.S. crude stocks are expected to have declined by 1.1 million barrels last week, with refiners ramping up production to offset worries over summer fuel supplies, a Reuters poll of analysts showed.
Gasoline stocks are seen rising by 300,000 barrels last week and distillate stocks 800,000 barrels in U.S. Energy Information Administration (EIA) data due at 1430 GMT on Wednesday.
(Additional reporting by Angela Moon in Seoul and Randy Fabi in London)