WINNIPEG, Manitoba, March 7 (Reuters) - TC Energy's ( TRP )

Keystone oil pipeline is offline due to operational

issues, cutting off a major conduit of Canadian oil to the

United States, three industry sources said on Thursday.

The 622,000 barrel-per-day pipeline has been dogged by

problems, including a 2022 spill in rural Kansas.

Calgary, Alberta-based TC did not immediately respond to a

request for comment.

TC shares were slightly higher in Toronto.

Keystone, stretching 4,850 km (3,000 miles), transports oil

from Alberta to Nebraska, where it splits, with one arm running

east to the Midwest and the other running south to the U.S.

crude storage hub in Cushing, Oklahoma and to the Gulf, where it

is processed by refiners or exported.

Last year, TC said it planned to spin off its liquids

business, including Keystone, to focus on transporting natural

gas. The company has been selling assets to reduce debt.