Traders said that purchases of Nigerian oil for October from the United States were at significantly higher levels than for earlier months.
Nigeria's state oil company raised its official selling price for Bonny Light to dated Brent plus 60 cents and Qua Iboe to dated Brent plus 94 cents.
Nigerian oil is well suited to meet a gap in the market met by what some analysts see as lower production on shale oil.
Traders were waiting to guage whether demand for November-loading Angolan cargoes would be any better than that for October.
Differentials for October fell due to a sharp drop in demand from China.
Angola is set to export 55 cargoes, about 1.77 million barrels per day (bpd), of crude oil in November, down from 1.83 million bpd planned in October, a provisional loading schedule showed on Thursday.
ANGOLA
* Two Girassol cargoes for October loading were still on offer to add to the 55 cargoes for November.
* Girassol was assessed at between dated Brent minus 50 cents to dated Brent minus $1.
NIGERIA
* Qua Iboe was notionally valued at dated Brent plus $1.20, in line with Tuesday.
* More than 15 cargoes of Nigerian crude for October loading are still available, one trader estimated.
TENDERS
* A tender from Indian refiner IOC was expected to be announced on Thursday, though traders had not heard the result.
* Uruguay's ANCAP bought a cargo of Bonny Light from Shell, one trader said. (Reporting by Simon Falush; Editing by David Goodman)
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