Demand for Nigerian crude improved slightly on Wednesday but traders said differentials were yet to recover because of a large overhang of cargoes for April and May.
Glencore sold a cargo of Akpo crude oil to India's BPCL at a small premium to dated Brent, but traders said the rest of the cargoes for the tender were awarded from Libya.
Increasing Libyan exports has sapped demand for Nigerian grades which are similar in quality.
Traders said between 20-30 cargoes of Nigerian crude oil were still unsold from the April-May programmes.
* Qua Iboe: Assessed unchanged at between dated plus $2.25-$2.50 a barrel, down around 30 cents from earlier this week.
* Traders said U.S. demand was still muted, although Vitol was heard to have sold an Escravos tanker to Petrobras.
* "Flow to the States is minimal. Light, sweet is plentiful in the U.S. so there is limited W. African demand," said a West African crude oil trader.
* Akpo: Assessed between dated plus 0.20-0.40 cents.
* Traders said around 7-8 cargoes remained from the May Angola programme, including Nemba, Pazflor and Plutonio.
* All of the May-loading Djeno cargoes have now sold, industry sources said. At least three of the cargoes were heard to be sold into the Asian market.
* Glencore won a tender issued by India's Bharat Petroleum Corp to supply Nigeria's Akpo grade for May loading, trading sources said on Wednesday.
* Traders said Libyan oil may also have been awarded as part of the tender but details were unclear.