Potash Corp, the world's biggest fertilizer maker, had earlier announced a six-week shutdown from December 25 through February 4 at the mine. It is extending the shutdown, which amounts to about 200,000 tonnes of potash, a key crop nutrient, Potash Corp spokesman Bill Johnson said in an email.
The company, which has typically matched supply to demand, announced production cuts at its Allan and Lanigan mines in Saskatchewan earlier this winter, saying that it saw a seasonal slowdown in demand.
Fertilizer demand is in a seasonal lull, but should resume as the U.S. spring planting season approaches, said analyst Edlain Rodriguez of Lazard Capital Markets, in a note to clients.
The total volume of Potash Corp's production cuts is nearly 1.2 million tonnes of potash, representing about 10 percent of Potash Corp's operational capacity, Rodriguez said.
Other Canadian potash miners, Mosaic and Agrium, recently told Reuters they were not planning to cut production.
Potash Corp shares dipped 0.6 percent and 0.4 percent in Toronto and New York respectively on Thursday afternoon.
Reporting by Rod Nickel in Winnipeg