Heavy Oil Discount Narrows for Fourth Straight Session

* WCS for September delivery in Hardisty, Alberta, settled at $13.10 a barrel below WTI, according to brokerage CalRock, having settled at $13.35 a barrel under the U.S. benchmark on Wednesday.

* It was the fourth straight session in which the heavy crude discount shrank, helped by Exxon Mobil restarting select units at its 251,800 barrel-per-day refinery in Joliet, Illinois, three weeks after it lost power following a storm.

* Joliet is one of the biggest single buyers of Canadian heavy crude, consuming about 8% of all Canadian exports, said Rory Johnston, founder of the Commodity Context newsletter.

* Global oil prices settled higher for the third consecutive session, after U.S. jobs data eased demand concerns and war in the Middle East helped prices recover from an eight-month low on Monday.

(Reporting by Nia Williams in British Columbia; Editing by Anil D’Silva)