CALGARY, Alberta, Aug 6 (Reuters) - Canadian heavy crudeprices weakened on Tuesday as oil sands production increased andtraders braced for planned maintenance that would likely weighon demand next month.
Western Canada Select heavy blend for September deliverylast traded at $23.50 per barrel below the West TexasIntermediate benchmark, according to Shorcan Energy brokers.
That compares with a settlement price of $22.00 per barrelbelow WTI on Friday. Markets were closed on Monday for aCanadian holiday.
Traders in Calgary said anticipation of planned maintenancein September at Husky Energy Inc's 82,000 barrel perday heavy oil upgrader in Lloydminster, Saskatchewan, waspushing prices lower.
Long-awaited production from Imperial Oil's Kearloil sands project also meant supply was plentiful.
"It's actually showing up," one Canadian crude trader said.
Imperial has said Kearl, which was originally intended tostart producing in December 2012, would reach full capacity of110,000 bpd over the summer.
Shell Canada is planning a full turnaround at its100,000 bpd Scotford, Alberta, refinery. The refinery runs lightsynthetic crude that has been mined and upgraded at Shell'sAthabasca oil sands project.
Light synthetic crude from the oil sands for Septemberdelivery last traded at $2.00 per barrel above WTI, down from asettlement price of $2.35 per barrel above the benchmark onFriday.