STOCKHOLM (Reuters) - Shipping company Maersk is evaluating contingency strategies in Canada, the company said on Thursday after the country's two main freight rail companies shut down their networks over a labour dispute.

The Danish company, one of the world's largest container freight groups, said in an advisory to clients it was still accepting bookings from and to origins and destinations serviced by rail via Canadian ports.

"As we navigate the current situation affecting Canadian rail services, we are actively monitoring the evolving circumstances," it said.

"Our team is communicating with our rail partners and evaluating contingency strategies as the situation develops."

Canadian National Railway ( CNI ) and Canadian Pacific Kansas City ( CP ) locked out some 10,000 workers on Thursday in an unprecedented stoppage that will grind railway freight in the country to a halt and also affect the United States.