CANADA-CRUDE-Western Canada Select heavy crude discount narrows

April 11 (Reuters) - The discount of Western Canada Select (WCS) heavy crude to the North American benchmark West Texas Intermediate futures (WTI) CLc1 narrowed on Friday, even as the Keystone oil pipeline from Canada to the U.S. remained shut down for a fourth consecutive day.

WCS for May delivery in Hardisty, Alberta, settled at $9.60 a barrel under WTI, according to brokerage CalRock, after having settled at $9.85 under the U.S. benchmark on Thursday.

The Keystone oil pipeline from Canada to the U.S. was shut on Tuesday after an oil spill in North Dakota. South Bow, owner and operator of the 4,327-km (2,689-mile) pipeline, was on Friday still investigating the cause of the leak and had not provided a timeline for the restart.

* The WCS discount widened in the immediate aftermath of the Keystone shutdown, but continues to be historically tight due to U.S. sanctions on heavy crude-producing countries such as Venezuela, as well as lower heavy crude exports from Mexico.

* The differential on Canadian heavy crude also tends to narrow when global oil prices are lower, in part because lower prices mean less competition for pipeline space for Canadian producers.

* Global oil prices saw volatile price swings this week as U.S. President Donald Trump's new tariff regime forced traders to reassess the geopolitical risks facing the crude market.