CANADA CRUDE-Heavy grades lifted by Whiting crude unit restart

* Sept WCS trades at $14.65/bbl below WTI

By Nia Williams

CALGARY, Alberta, Aug 25 (Reuters) - Canadian heavy crude differentials tightened on Tuesday after BP Plc restarted a crude unit at its 413,500 barrel-per-day Whiting, Indiana, refinery weeks earlier than initially expected.

BP said production at Whiting, one of the largest consumers of Canadian crude in the Midwest, would return to normal levels in the coming days, boosting demand for heavy crude.

Western Canada Select heavy blend crude for September delivery last traded at $14.65 per barrel below the West Texas Intermediate benchmark, tightening from $15.50 per barrel below WTI on Monday, according to Shorcan Energy brokers.

Differentials blew out to their widest level in a year when news of the malfunction at Whiting's largest crude unit, combined with outages on two key Enbridge Inc (Toronto: ENB.TO - news) pipelines, reached the market just over two weeks ago.

The earlier-than-expected restart provides some relief to Canadian crude producers who are struggling with a global crude rout that dragged the outright price of WCS close to $20 last week.

Outright WCS last traded at around $24.66 a barrel.

There was no trade in light synthetic crude from the oil sands for September delivery, according to Shorcan.

The Canadian crude market is outside the nearly three-week-long trading "window" - from the first of each month until the day before pipeline nominations are due - in which the bulk of activity takes place. (Editing by Alan Crosby)