WINNIPEG, Manitoba, March 8 (Reuters) - TC Energy ( TRP )

temporarily shut down the Keystone oil pipeline on

Thursday to investigate a landowner's report about a possible

leak that proved unfounded, a spokesperson for a U.S. pipeline

regulator said on Friday.

TC told the Pipeline and Hazardous Materials Safety

Administration (PHMSA) about the reported leak, then conducted

aerial observation and water analysis that found no evidence of

a spill before restarting the line, PHMSA said. It was not clear

where the leak was reported.

Calgary, Alberta-based TC did not respond to a request for

comment on Friday. On Thursday, the pipeline operator said it

had suspended service as a precautionary measure.

The shutdown of the 622,000 barrel-per-day (bpd) pipeline

interrupted the flow of Canadian oil from Alberta to Nebraska,

where the line splits, with one arm running east to the Midwest

and the other running south to the U.S. crude storage hub in

Cushing, Oklahoma.

The outage took down the entire Keystone system for five

hours, according to real-time pipeline monitoring by consultancy

Wood Mackenzie.

The pipeline has been dogged by problems, most recently a

major spill in rural Kansas in 2022.

Wood Mackenzie said as of Friday morning, Keystone flows had

rebounded to their pre-shutdown level of more than 600,000 bpd.

TC shares dipped 0.4% in New York.