* July WCS last at $18.70/bbl under WTI
* July synthetic last at $0.20/bbl under WTI
CALGARY, Alberta, June 3 (Reuters) - Canadian heavy oilprices strengthened on Monday on prospects of higher demand asrefineries wrap up maintenance work.
Western Canada Select heavy blend for July delivery lasttraded at $$18.70 per barrel under the West Texas Intermediatebenchmark, according to Shorcan Energy Brokers. That compareswith a settlement price on Friday of $19.25 per barrel belowWTI.
Exxon Mobil Corp is expected to soon completeplanned maintenance at its 238,600 barrel per day refinery atJoliet, Illinois. The refinery, which uses Canadian crude, hasbeen undergoing an overhaul since April 14.
As well, sources said last week that BP Plc shouldstart an upgraded crude distillation unit at its 405,000 barrelper day (bpd) Whiting, Indiana, refinery in late June.
Synthetic crude from the oil sands weakened slightly.Synthetic for July delivery last traded at 20 cents per barrelbelow WTI, down from a settlement price on Friday of 15 centsper barrel below the benchmark.