CALGARY, Alberta, Nov 27 (Reuters) - Canadian heavy crudedifferentials widened in thin trade on Wednesday, with marketschoppy in the run-up to the Thanksgiving holiday in the UnitedStates.
The Canadian crude market is outside the roughly three-weeklong trading "window" - from the first of the month until theday before pipeline nominations are due - when the bulk oftrading takes place.
Western Canada Select heavy blend for December delivery lasttraded at $34.00 per barrel below the West Texas Intermediatebenchmark, according to Shorcan Energy brokers.
That compares with a settlement price of $32.00 per barrelbelow WTI on Tuesday.
Traders in Calgary said the wider discount on Wednesday wasdown to thin liquidity and the fact that some market players sawthe recent rally in WCS prices as being overdone.
The discount on WCS has narrowed sharply in recent weeksfrom $41.50 per barrel below WTI, the widest differential in 10months, which was hit on Nov. 5.
News that BP Plc began the lengthy start-up processon a new 102,000 barrel per day coker at its Whiting, Indiana,refinery, in mid-November helped WCS prices rally.
The coker is a crucial step in a $4-billion overhaul ofWhiting that will allow it to run mostly heavy Canadian crude.
"News they have started up the new coker is the maincatalyst behind the narrowing of the WCS differential to WTI,"said David Bouckhout, senior commodities analyst at TDSecurities.
Bouckhout said the Co-op refinery in Regina, Saskatchewan,returning to full capacity after a fire earlier this month hadalso helped support crude prices.
There were no trades in light synthetic crude from the oilsands for December delivery, according to Shorcan Energybrokers. On Tuesday synthetic crude settled at $13.00 per barrelbelow the WTI benchmark.
Shell Canada reported planned maintenance at its100,000 bpd Scotford refinery near Edmonton, Alberta. Therefinery runs light synthetic crude that has been mined andupgraded at Shell's Athabasca oil sands project.