Oil prices fell on Thursday as OPEC+ stuck to its policy of incrementally boosting output, even as the Omicron coronavirus variant unsettles markets and threatens to undercut fuel demand.

       Brent crude futures were $1.21, or 1.7%, lower at $67.66 a barrel by 1430 GMT while U.S. West Texas Intermediate (WTI) crude futures fell $1.24, or 1.8%, to $64.33.

       Global oil prices have lost more than $10 a barrel since last Thursday, when news of Omicron first shook investors.

       The Organization of the Petroleum Exporting Countries (OPEC) and its allies, together known as OPEC+, decided on Thursday to release more oil into the market in January in line with previous months.

       Since August the group has been adding an additional 400,000 barrels per day (bpd) of output to global supply each month, gradually winding down record cuts agreed in 2020.

       Fears over the impact of the Omicron variant have risen after the first case was reported in the United States.

       U.S. Deputy Energy Secretary David Turk said President Joe Biden's administration could adjust the timing of its planned release of strategic crude oil stockpiles if global energy prices drop substantially.

       Also weighing on the market was weekly U.S. inventory data showing that U.S. crude stocks fell less than expected last week, while gasoline and distillate inventories rose much more than expected while demand weakened.