Nigerian crude for August is selling slowly, traders said on Wednesday, and sellers were heard to be trimming offer levels for grades such as Qua Iboe amid ample supplies, Reuters reports.

The number of unsold August cargoes remains at more than 40, a relatively large number compared to earlier months, traders said. As few as six cargoes for July were still looking for buyers.

Qua Iboe, the largest export stream, was valued at dated Brent plus 35 cents, the lowest since December 2015. One seller was offering an August cargo at dated plus 80 cents, 10 cents lower than an offer level reported on Tuesday.

Some Nigerian grades including distillate-rich Forcados are selling more briskly, however, supporting differentials.