Brent's premium against U.S. crude rose as high as $15.99, but narrowed at the close to $15.34 as U.S. government data showed that crude oil stockpiles at the U.S. delivery point in Cushing Oklahoma, while reaching a new record, edged up only modestly from the previous week's levels.
Traders expect that the reversal earlier this month of the Seaway pipeline from the U.S. delivery point in Cushing, Oklahoma, to the main U.S. refining center in Gulf Coast, will help ease the glut of oil in the U.S. Midwest and possibly move U.S. and Brent crude prices closer. .
Brent's volume topped more than nearly 670,000 contracts, 23 percent above its 30-day average, ahead of the U.S. trading volume of almost 612,000 contracts, 18 percent atop its 30-day average, according to Reuters data.
EURO ZONE CRISIS
The crisis in the euro zone continued to dominate market sentiment.
"Markets have been fairly tight but it's all these euro zone worries that have really spooked the oil markets," said Rob Montefusco, a trader at Sucden Financial.
Mario Draghi, president of the European Central Bank, warned that the ECB could not fill the vacuum created by the lack of action by national governments.
Spain's center-right government has so far failed to spell out how it plans to finance a 23.5 billion euro ($29 billion) rescue of Bankia, the country's fourth largest lender.
GASOLINE FALLS, JOBS DATA AWAITED
U.S. gasoline futures closed the month at a four-month low, pressured by continuing weak demand, despite falling stockpiles.
U.S. gasoline for June delivery expired and settled at $2.8250 a gallon, down 3.32 cents, the lowest close for front-month gasoline since Jan. 24. Prices fell as investors ignored data showing U.S. gasoline inventories fell last week to the lowest level since 2008.
On Friday, traders shift their sights to the all-important U.S. nonfarm payrolls and unemployment data for May to see if the economy's modest recovery is still holding.
U.S. employers were expected to have hired 150,000 new workers during the month, after a disappointing rise of just 115,000 in April, according to a Reuters poll. The unemployment rate probably remained unchanged at the 8.1 percent level, the poll also showed.