With differentials unchanged, pure Alaska North Slope (ANS) crude prices rose with an 18 cent gain in Nymex December crude oil futures.

West Coast spot crude markets remained following the weekend, while buyers tried to push discounts higher for November ANS.

The last ANS deal was struck Oct. 9 at a discount of $1.025 a barrel off benchmark US crude, November West Texas Intermediate (WTI).

Buyers claimed that normal production levels and weak margins were discouraging them from buying ANS this week.

Some buyers saw the differential widening to $1.25 below WTI.

The notional price for West Coast ANS rose to $13.28/13.45 a barrel from $12.95/13.11.

The biggest ANS producer said his company had November cargoes available but declined to make a specific offer to refiners.

Buyers said between three and five cargoes were available for November delivery.

Inforeign crudes, three cargoes of Oriente, an ANS substitute, were reportedly sold by two Gulf Coast trading houses and a West Coast refinery.

A cargo of Kuwait was sold between two West Coast refineries, but neither was available to confirm the deal.

Several major oil firms cut their posted prices for West Coast crudes by 50 cents to 75 cents a barrel last week, bringing their prices in line with a 80-cent slide in oil futures that day.