April 15 (Reuters) - The discount on Western Canada

Select (WCS) heavy crude versus the North American benchmark

West Texas Intermediate (WTI) narrowed slightly on Monday:

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

$13.20 and $13.25 a barrel below WTI, according to brokerage

CalRock, after closing at $13.45 a barrel below the benchmark on

Friday.

* Canadian heavy crude differentials have been largely

steady after strengthening at the start of the month on news

that the 600,000 barrel-per-day Trans Mountain pipeline

expansion project will start operating on May 1.

* Canadian oil and gas producer Tamarack Valley Energy ( TNEYF )

has temporarily shut in about 6,200 barrels of oil

equivalent per day (boepd) of production after a fire at a

third-party gas plant at Mitsue, Alberta.

* Global oil prices slipped lower after Iran's weekend

attack on Israel proved to be less damaging than anticipated,

easing concerns of a quickly intensifying conflict that could

displace crude barrels.

(Reporting by Nia Williams in British Columbia; Editing by

Subhranshu Sahu)