MONTREAL (Reuters) -The Canada Industrial Relations Board ordered on Saturday a halt to work stoppages at the country's largest railways, signaling an end to an unprecedented service disruption at both main freight rail carriers that threatened to hammer the country's export-driven economy. 

The independent labor tribunal made the decision after Canada asked it on Thursday to end an impasse in separate talks between more than 9,000 Teamsters members, and Canadian National Railway and Canadian Pacific Kansas City.

Along with ordering an end to the stoppage, the board implemented government requests to impose binding arbitration on the parties to reach new deals and to impose a continuation of the existing contracts until new agreements are reached.

The board's decisions are the latest twist in the labor disputes at CN and CPKC, which locked out Teamsters members on Thursday, triggering a simultaneous rail stoppage that business groups said could inflict hundreds of millions of dollars in economic damage. 

Canada, the world's second-largest country by area, relies heavily on trains to transport a wide range of commodities and goods. 

The labor board's decision will avert a planned strike on Monday at 10 a.m. ET (1400 GMT) by locomotive engineers, conductors and other workers at Montreal-based CN just days after Canada's largest railway ended a lockout and began restoring service. The Teamsters confirmed its CN workers would not strike on Monday.

CPKC workers had remained locked out since Thursday until the CIRB's decision.

"This decision by the CIRB sets a dangerous precedent," said Paul Boucher, president of the Teamsters Canada Rail Conference. "It signals to corporate Canada that large companies need only stop their operations for a few hours, inflict short-term economic pain, and the federal government will step in to break a union. The rights of Canadian workers have been significantly diminished today." 

A CN spokesperson said the company would have preferred a negotiated agreement, but "we are satisfied that this puts an end to the labor stoppage."

CPKC was not immediately available for comment.

The disruption could have drastically affected farmers and agriculture companies in both Canada and the United States.

Wade Sobkowich, executive director of the Western Grain Elevator Association, which represents grain companies, said they had urged the government for weeks to refer the matter to the CIRB.

"It means that the government has really listened to what Canadians were telling them. We can't take a self-inflicted wound on the economy."

The Teamsters union has said it will lawfully abide by any decision from the CIRB, but is prepared to file challenges in federal court if necessary.

On Thursday, Canada's Labour Minister, Steven MacKinnon, said his decision to refer the matter to the CIRB would survive a court challenge given his broad power under the country's labor code.

The Teamsters union wants its members' working conditions and pay to be determined by bargaining, despite disputes with CN and CP over scheduling, shift duration and availability. CN, for example, wants employees to work up to 12-hour shifts, compared with 10 hours in the current agreement, a move opposed by the union.