TransCanada Corp. has shut down its Keystone oil pipeline after it detected a "small anomaly" on the outside of the pipe.
Company spokesman Grady Semmens says the line, which delivers oilsands crude to refineries in Illinois and a storage hub in Oklahoma, has been shut as a precaution.
He says no leaks have been detected on the system, which is expected to be offline for three days while the company goes in for a closer look at the pipe.
TransCanada has a proposal called Keystone XL to expand the system and extend its reach to the U.S. Gulf Coast.
After a series of delays, the U.S. government is expected to make a decision on the controversial $7.6-billion expansion early next year.
