April 12 (Reuters) - The discount on Western Canada

Select (WCS) heavy crude versus the North American benchmark

West Texas Intermediate (WTI) tightened on Friday:

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

$13.45 a barrel below WTI, according to brokerage CalRock, after

closing at $13.60 a barrel below the benchmark on Thursday.

* Canadian heavy crude differentials have strengthened this

month on news that the 600,000 barrel-per-day Trans Mountain

pipeline expansion project is set to start operating on May 1.

* "We expect the start-up of TMX should eliminate

apportionment on the pipeline systems and lead to refiners

competing to buy heavy oil," BMO Capital Markets analyst Randy

Ollenberger said in a note to clients.

* BMO said the differential could fall below $10 a barrel,

helped by the ramp up of the Pemex Dos Bocas refinery in Mexico

boosting demand.

* Oil rose around 1% on geopolitical tensions in the Middle

East but posted a weekly loss on a bearish world oil demand

growth forecast from the International Energy Agency (IEA) and

worries about slower U.S. interest rate cuts.