West African crude oil sellers are struggling to find buyers for up to 26 December- and January-loading cargoes due to stiff competition from plentiful and cheaper alternative supplies, Reuters new agency reports citing traders and analysts.

The amount of unsold Nigerian and Angolan crude, analysts say, is a symptom of a wider oil market surplus.

"The overhang of West African cargoes partly reflects the broader global crude supply surplus emerging in Q1," said Victoria Grabenwoger of analytics firm Kpler.

Approximately 20 million barrels of Nigerian oil for December and January loading remained unsold by Thursday, according to two traders, while Angola's December-January programmes still had as many as five to six cargoes available.

These cargoes have slowed the start of the trading cycle for February cargoes even though Angola's loading schedule and term nominations have already been released.

Unsold oil

Such a large amount of unsold oil is unusual, especially for the current month, given the West African trade cycle is typically closer to two months ahead. Estimates for both countries' overhang were as high as 40 million barrels earlier this week.

Supplies from the Middle East are displacing medium and heavy West African grades in Asia as lowered official selling prices in January and shorter voyages give those grades a competitive edge, the analysts said.

India's oil imports from Russia have remained resilient despite tightening Western sanctions, displacing medium-heavy density West African crudes, while light to medium-density West African grades are struggling to compete with supplies from Argentina and Brazil, two traders said.

Nigeria has also been left to market more oil because of reduced imports by Africa's largest oil refinery, the 650,000 barrels-per-day Dangote plant, which will in January undergo maintenance, Kpler's Grabenwoger said.