TORONTO (Reuters) - Contract talks between Canadian Pacific Railway (>> Canadian Pacific Railway Limited) and the Teamsters Canada Rail Conference (TCRC) have stalled, the union representing about 3,800 locomotive engineers and conductors at the country's No. 2 railway said on Friday.

The Teamsters said it filed an official request on Wednesday for mediation, saying the main point of contention with management was worker fatigue and how to manage it.

"They want significant concessions, a dramatic increase in working hours out of each employee, provide less rest hours, and within an industry plagued by fatigue already," Doug Finnson, the Teamsters' chief negotiator, said in a statement.

CP Rail, which also has large operations in the United States, said it has offered wage increases and an improved benefit plan, among a number of other contract enhancements, and that it had asked for contract discussions to begin a year ago. The existing labor contract expires on Dec. 31.

"To be clear, it was the union that terminated the negotiation sessions this week and we are waiting to hear back from them," CP spokeswoman Breanne Feigel wrote in an email.

"On the subject of fatigue, CP has proposed a scheduling framework that allows for greater predictability such that these employees will know when they will work and when they will be off."

Rest provisions were a key issue in contract negotiations earlier this year between Canadian National Railway (>> Canadian National Railway Company), the country's biggest railway, and the Teamsters.

Union members at CN Rail voted down a tentative contract deal because of doubts the railway would respect provisions for rest, but a strike was averted when Canada's Conservative government said it would use back-to-work legislation to keep operations going.

(Reporting by Solarina Ho; Editing by Peter Galloway)