By Stephanie Kelly
NEW YORK (Reuters) - Oil prices rose on Friday, on track for their biggest quarterly rise in a decade, as U.S. sanctions against Iran and Venezuela as well as OPEC-led supply cuts overshadowed concerns over a slowing global economy.
The May Brent crude oil futures contract, which expires Friday, gained 48 cents to $68.30 a barrel by 10:40 a.m. EDT (1440 GMT), set for a gain of 27 percent in the first quarter. The more-active June contract was up 35 cents at $67.45 a barrel.
U.S. West Texas Intermediate (WTI) futures rose 63 cents to $59.93 a barrel, and were on track for a rise of 32 percent over the January-March period.
For the two benchmarks, the first quarter was the best-performing quarter since 2009, when both gained about 40 percent.
U.S. sanctions on Iran and Venezuela have boosted oil prices this year, as the sanctions have restricted crude exports out of the countries.
The United States is keen to see that Malaysia, Singapore and others are fully aware of illicit Iranian oil shipments and the tactics Iran uses to evade sanctions, a top U.S. sanctions official said on Friday.
Sigal Mandelker, under-secretary of the Treasury for Terrorism and Financial Intelligence, told reporters in Singapore that the United States had placed additional "intense pressure" on Iran this week.
"It seems that the Trump administration may be more serious about imposing sanctions on Iranian oil this time around," said John Kilduff, a partner at Again Capital LLC in New York.
Meanwhile, the United States has instructed oil trading houses and refiners around the world to further cut dealings with Venezuela or face sanctions themselves, even if the trades are not prohibited by published U.S. sanctions, three sources familiar with the matter said.
Also lifting prices this year has been a deal between the Organization of the Petroleum Exporting Countries and allies such as Russia to cut output by around 1.2 million barrels per day, which officially started in January.
OPEC and its allies are scheduled to meet in June to set policy, but some cracks in the union are emerging.
OPEC's de facto leader Saudi Arabia favors cuts for the full year while Russia, which joined the agreement reluctantly, is seen as less eager to restrict supply beyond September.
The market has also been supported by slower output growth in the U.S., the world's top crude producer, where record production has steadied at a record over 12 million bpd since mid-February.
U.S. drillers last week cut the number of oil rigs, an indicator of future production, for five straight weeks. This week's data is due at 1 p.m. EDT.
Gains, however, have been capped this quarter by concerns about a slowing global economy that could hit crude demand.
U.S. consumer spending rebounded less than expected in January and incomes rose modestly in February, suggesting the economy was fast losing momentum after growth slowed in the fourth quarter.
Elsewhere, three of China's top state-controlled bank posted their weakest quarterly profit growth in more than two years.
Still, Barclays (LON:BARC) bank forecast oil prices "are likely to move still higher in Q2 and average $73 per barrel ($65 WTI), and $70 for the year."
A monthly Reuters survey of economists and analysts forecast Brent would average $67.12 a barrel in 2019, about 1 percent higher than the previous poll's $66.44.
