WINNIPEG, Manitoba—TransCanada Corp restarted a section of the Keystone oil pipeline on Feb. 19, following a leak in Missouri earlier this month, company spokesman Terry Cunha said.

TransCanada had shut an arm of Keystone from Steele City, Neb., to Patoka, Ill., on Feb. 6 after leaking 43 barrels of crude oil.

The shutdown restricted the flow on the 590,000 barrels-per-day Keystone pipeline system, a critical artery taking Canadian crude from northern Alberta to refineries in the U.S. Midwest.

The line restarted with a 20% reduction of pressure, a spokesman for the U.S. Pipeline and Hazardous Materials Safety Administration said.

TransCanada shares finished up 0.3% at C$56.90 in Toronto.