(Reuters) - Canadian Pacific Railway Ltd (CP.TO) said on Saturday the union representing nearly 5,000 engineers, conductors and traffic controllers submitted a 72-hour strike notice, giving workers the right to walk off their jobs as early as Wednesday.
Canada's second largest railroad said it would carry on with negotiations with the Teamsters Canada Rail Conference, with the assistance of a federal mediator.
The talks come at a time when CP is under extreme pressure to improve its operating performance, currently the worst in the industry.
On Thursday, the railway's management conceded defeat in a proxy battle with New York activist shareholder William Ackman. Chief Executive Fred Green and Chairman John Cleghorn both quit after a boardroom coup, clearing the way for a management overhaul.
Contract talks, which began in October 2011, have not resolved issues on pensions, work rules, wages, fatigue management and work-life balance, the union says. The previous contract expired on January 1.
CP has said pension costs are hurting its operating efficiency and the company's ability to make investments that would bring growth.
It said it had made C$1.9 billion in solvency deficit contributions to its pension plan over the past three years and that it must now make its pension and retirement benefits comparable with industry standards.
Reporting by Frank McGurty; Editing by Peter Cooney