Brent and U.S. crude futures fell to the lowest since 2003 following the lifting of the sanctions at the weekend.
Iran is ready to increase its crude exports by 500,000 barrels a day, the deputy oil minister said on Sunday, hours after international sanctions on Tehran were lifted, removing an obstacle to exports.
NYMEX crude for February delivery was down 86 cents at $28.56 a barrel, after falling more than $1 earlier to $28.36, the lowest since Oct. 30, 2003.
London Brent crude for March delivery was down $1.14 at $27.80 a barrel by 2333 GMT, after touching an intraday low of $27.70 earlier, the lowest since Nov. 25, 2003.
