Canada crude - Heavy grades supported by Whiting ramp-up

* April WCS trades at $21.90 per barrel below WTI

* April synthetic trades at $3.00 per barrel below WTI

CALGARY, Alberta, March 10 (Reuters) - Canadian heavy crude prices were steady in thin trade on Monday, supported by the gradual ramp-up in demand from BP Plc (LSE: BP.L - news) 's Whiting, Indiana, refinery.

Western Canada Select heavy blend for April delivery was last trading at $21.90 per barrel below the West Texas Intermediate benchmark, according to Shorcan Energy brokers.

That compares with a settlement price of $21.85 per barrel below the benchmark on Friday.

WCS prices have traded in a range roughly between $18.00 and $25.00 per barrel below WTI since the start of January, helped by Whiting's increasing its heavy crude intake.

BP spent $4 billion revamping Whiting last year to enable the refinery to run more cheap Canadian crude.

Last week the company said the refinery, which is currently processing 350,000 barrels per day, would ramp up processing of heavy crudes to 280,000 bpd in the next few months from the current 160,000 bpd.

"That helps strengthen WCS prices and helps offset the cost differential that is coming from pipeline constraints," said Barclays (LSE: BARC.L - news) analyst Michael Cohen.

Oil sands crude tends to trade at a discount because congested export pipelines can leave crude bottlenecked in Alberta.

Light (Other OTC: LGSXY - news) synthetic crude from the oil sands strengthened slightly to $2.75 per barrel below WTI, compared with a settlement price on Friday of $3.00 per barrel below the benchmark.

(Reporting by Nia Williams; Editing by Leslie Adler)