The rail operator was given four months to identify and remove any wheels handled by the Manitoba facility after investigators determined loose wheels were the cause of a derailment in Ontario on Jan. 31, 2006, CTV News reported Friday.

Canadian Transport Minister Lawrence Cannon said in a news release loose wheels on a CPR freight engine that had been serviced in CN's Winnipeg plant were behind the accident in which the engine derailed before hitting a switch, knocking 11 other cars off the tracks on Jan. 31, 2006.

More than 12 miles of track were damaged in the incident but no one was injured, the report said.

The board said in its announcement as many as 12,000 wheel sets by CN, CPR and U.S. rail lines had been processed at the Winnipeg site, CTV said.