Brent oil edged higher on Thursday after Iran rejected calls for direct talks with the United States, while U.S. crude prices tumbled on concerns about growing domestic stockpiles in the Midwest.
Brent's premium over West Texas Intermediate crude rose to more than $21 a barrel after a report that a refinery in the U.S. Midwest would remain shut for maintenance longer than expected, raising expectations the glut of crude oil at Cushing, Oklahoma, the delivery point for U.S. futures would swell further.
BP's Whiting, Indiana, refinery reportedly delayed the restart of a crude unit by up to three months, according to a news report cited by traders.
The international benchmark found supports after Iran's supreme leader, Ayatollah Ali Khamenei, rejected a U.S. offer to hold direct talks, denting hopes for the resolution of disputes over Tehran's nuclear program.
Traders have been closely watching the stand off with Iran due to concerns about supplies from the OPEC nation, one of many tensions in the Middle East that have held sway over oil markets over the past year.
"The Brent market is a little more sensitive to geopolitical risk and tensions, and reports that the leader in Iran said he doesn't want to engage in direct talks with the United States, that ratcheted up a bit of the geopolitical risk," said Gene McGillian, analyst at Tradition Energy in Stamford, Connecticut.
Oil markets have been boosted in recent weeks by signs that the economies of the United States and China, top oil consumers, are recovering at quicker paces.
The number of Americans filing new claims for jobless benefits fell last week and put the four-week average reading at a near five-year low, but other data showed a productivity drop in the fourth quarter due to weak economic output.
The Chinese economy ended seven straight quarters of slowing growth with a 7.9 percent lift in the fourth quarter.