SINGAPORE, Jan 6 (Reuters) - Oil prices lost ground on Thursday, easing from their highest levels in more than a month as OPEC+ producers stuck to a plan to boost production and U.S. fuel stockpiles surged amid declining demand. The global benchmark Brent crude futures fell 87 cents, or 1.08%, to $79.93 a barrel, as of 0154 GMT. U.S. West Texas Intermediate (WTI) crude futures lost 62 cents, or 0.8%, to $77.23 a barrel. On Wednesday, both contracts climbed to their highest since late November. OPEC+, a group that includes members of the Organization of the Petroleum Exporting Countries, Russia and other producers, agreed on Tuesday to add another 400,000 barrels per day (bpd) of supply in February, as it has done each month since August. U.S. crude oil stockpiles fell last week while gasoline inventories surged more than 10 million barrels, the biggest weekly build since April 2020, as supplies backed up at refineries due to reduced fuel demand. read more Minutes from a U.S. Federal Reserve meeting that showed policymakers may have to raise rates more quickly than markets anticipated put additional pressure on oil prices. U.S. stocks slid and Treasury yields jumped on Wednesday after the meeting minutes were released. The minutes also indicated the Fed could reduce its overall asset holdings to tame high inflation. Meanwhile, TC Energy"s (TRP.TO) 590,000-bpd Keystone oil pipeline was shut on Tuesday evening for unplanned maintenance, the company said on Wednesday, as parts of western Canada grappled with frigid winter weather. read more