Oil slipped below $78 a barrel on Monday as OPEC+ looked set to agree to a further oil output increase and concern persisted about the demand impact of rising coronavirus cases, despite hopes of a further recovery in 2022.
OPEC and its allies, or OPEC+, are expected on Tuesday to agree to the output hike.
The Omicron coronavirus variant has brought record case counts and dampened New Year festivities worldwide, with more than 4,000 flights cancelled on Sunday.
Brent crude was down 42 cents, or 0.5%, to $77.36 a barrel at 1402 GMT, having earlier risen as high as $79.05. U.S. West Texas Intermediate (WTI) crude slipped 52 cents or 0.7%, to $74.69.