Bloomberg reported that Bakken oil’s premium to WTI dropped after Marathon Petroleum Corp. (NYSE:MRO) continued its maintenance work at Illinois refinery.

As quoted in the market news:

Bakken oil’s discount widened $4.50 a barrel to $12 below U.S. benchmark WTI at 1:31 p.m. in New York, according to data compiled by Bloomberg. That’s the cheapest the graded has traded since March 23.

Click here to read the full Bloomberg report.