The 5,000 striking workers at Canadian National Railway Co. have ratified the company's latest contract offer and agreed to end a four-week strike, their union said on Friday.

The mechanics, sales clerks and container yard employees, accounting for almost one quarter of CN's workforce, voted by wide margins to accept the offer, the Canadian Auto Workers union said in a statement.

The strike, which began Feb. 20, would end immediately, the union said. Employees will return to work Saturday.

The three-year agreement provides wage increases of 3 percent a year, improved pensions and a signing bonus of C$1,000 (US$750).

Union members, on strike since Feb. 20, rejected an earlier proposal by the railroad that called for identical pay hikes.

CN, based in Montreal, also agreed to a key union demand to roll back a controversial disciplinary system to pre-2001 standards.

The strike had slowed intermodal and wheat export shipment as shippers scrambled for a shrinking supply of available railcars or shifted to trucks.