May 7 (Reuters) - The discount on Western Canada Select

(WCS) heavy crude versus the North American benchmark West Texas

Intermediate (WTI) narrowed further on Tuesday:

* WCS for June delivery in Hardisty, Alberta, traded at

$11.50 a barrel below WTI, according to brokerage CalRock, after

closing at $11.60 a barrel below the benchmark on Monday.

* Canadian heavy crude has traded at a discount of less than

$12 a barrel to WTI since the start of this month's trade cycle,

when the 590,000 barrel per day (bpd) Trans Mountain pipeline

expansion (TMX) started commercial operations.

* Canada's second-largest oil producer Suncor Energy ( SU )

reported record first-quarter production of 835,300 bpd, up

12.6% from a year earlier.

* Global oil prices closed slightly lower on signs of easing

supply concerns, while market participants shifted their focus

to U.S. stockpiles data due Wednesday.