U.S. oil producers, unfazed by the Omicron variant of the coronavirus and an anticipated lull in demand between the Christmas and New Year holidays, maintained production at a 2021 peak level during the final week of the year.

The U.S. Energy Information Administration (EIA) said Wednesday that domestic crude output held at 11.8 million b/d for the period ended Dec. 31. That was on par with the prior week, when production reached its highest weekly level for the year following a gradual recovery from the pandemic-induced slump of 2020. Output last week was up 7% from a year earlier.

Rampant spread of the Omicron variant in late December forced airline personnel to stay home and caused travel interruptions. This compounded an expected easing of demand for motor gasoline because...