Canadian National Railway Co and Teamsters Canada Rail Conference (TCRC) have reached a tentative agreement on labor contracts before the expiry of the current contract.

Details were not available, as the agreement needs to be ratified by TCRC members, a process expected to take about 60 days.

The contract covers about 1,800 CN locomotive engineers in Canada.

It's the first time we have reached a tentative agreement with CN before the expiration of the old contract, Rex Beatty, president of the TCRC, said in a statement.

Shares of CN, Canada's biggest railway, were trading down 1 percent at C$77.99 on Monday on the Toronto Stock Exchange. The wider TSX index was down 1.75 percent.