* WCS for April delivery in Hardisty, Alberta traded between
$15.35 and $15.70 a barrel under the WTI, according to brokerage
CalRock, having traded between $15.30 and $15.20 a barrel under
WTI on Monday.
* In recent weeks, the price of WCS for delivery in Hardisty
has been affected by crude quality discounting pressure at the
U.S. Gulf Coast.
* "We've been tightening for a while now, and it's all been
driven by quality related issues at the U.S. Gulf Coast," said
Rory Johnston, founder of the Commodity Context newsletter.
* Light synthetic crude from the oil sands for April
delivery traded $3.25 and $3.50 a barrel over WTI, according to
CalRock.
* Oil prices fell by $3 a barrel on Tuesday after comments
from U.S. Federal Reserve Chair Jerome Powell stoked rate hike
fears, the dollar strengthened and top crude importer China
issued weak data. (Reporting by Laura Sanicola)