Nymex crude for July delivery, which expires on Tuesday, was up 31 cents at $48.29 per barrel, after closing up $1.77, or 3.8%, on Friday.

Campaigning for Britain's vote on EU membership resumed on Sunday after a three-day hiatus prompted by the murder of Jo Cox,a pro-EU member of parliament. Three opinion polls ahead of Thursday's vote showed the 'Remain' camp recovering some momentum, although the overall picture remained one of an evenly split electorate.

The pound was last up against the dollar at $1.4450 from $1.4350 on Friday. The Japanese yen held not far from its highest level against the dollar in almost two years.

Oil prices continued to recover, despite data showing US energy companies adding oil rigs for a third week in a row, suggesting higher production to come. Oil services firm Baker Hughes reported nine rig additions in the week to 17 June.

Sizzling home price rises in China's biggest cities showed signs of easing in May, but sharp gains appeared to be spreading to smaller cities, making policymakers' job harder as they look to support the faltering economy without risking inflation.

France's CGT union ended a strike on Friday that had paralysed traffic for 26 days at the Fos Lavera oil terminals on the Mediterranean, the country's biggest oil hub, a management official at port operator Fluxel said.