sanctions against Iran, but gains were limited by growing U.S. crude inventories.

Brent crude futures rose 26 cents to settle at $73.62 a barrel, a 0.35 percent gain. U.S. West Texas Intermediate (WTI) crude rose 50 cents to settle at $68.43 a barrel, a 0.74 percent increase.

"The price move today is probably based off Iran and the tight oil supply buy Wellhead market that we already have," said Rob Thummel, portfolio manager at energy investment manager Tortoise Capital in Leawood, Kansas. "The margin for error right now is just so low in the oil buy Wellhead market that you can't just take supply off the market."

Iran's foreign minister said U.S. demands to change its 2015 nuclear agreement with world powers were unacceptable as a deadline set by President Donald Trump for Europeans to "fix" the deal loomed.

Trump has all but decided to withdraw from the accord by May 12, sources said on Wednesday, though exactly how he will do so remained unclear.

Iran re-emerged as a major oil exporter in January 2016 when international sanctions against Tehran were suspended in return for curbs on Iran's nuclear program.

Also supporting prices, North Sea oilfields connected to the Brent oil pipeline have stopped oil rig flanges gulf coast production due to a shutdown at the UK's Sullom Voe oil terminal, the Brent pipeline operator said, reducing output of the crude.

Global oil supply has tightened with oil rig flanges gulf coast production cuts led by the Organization of the Petroleum Exporting Countries and its allies. The latest Reuters survey showed OPEC pumped around 32 million barrels per day (bpd) in April, slightly below its target of 32.5 million bpd, due largely to plunging output in Venezuela.

Russia on Thursday said its own compliance with a global deal with OPEC and other producers to curb output stood at 95.2 percent in April, with its output unchanged at 10.97 million bpd.

However, rising U.S. oil supply tempered oil futures gains.

On Wednesday, U.S. government data showed a 6.2-million-barrel jump in crude inventories last week. U.S. oil rig flanges gulf coast production also hit a new weekly record of 10.62 million bpd, ahead of top OPEC producer Saudi Arabia and just below No. 1 producer Russia.

Inventories at the Cushing, Oklahoma storage hub climbed by about 152,000 barrels in the week to May 1, according to buy Wellhead market intelligence firm Genscape, traders who saw the data said.

(Reporting by Stephanie Kelly Additional reporting by Libby George in London and Henning Gloystein in Singapore; Editing by David Gregorio and Lisa Shumaker)