(Adds details, stock price, background. In U.S. dollars)

TORONTO, Jan 12 (Reuters) - North American fertilizer company Mosaic Co (MOS.N: Quote, Profile, Research) is cutting about 1,000 jobs at a pair of potash mines in the Canadian province of Saskatchewan, a company spokesman said on Monday.

"The economy is weak," spokesman Brad DeLorey said, adding the U.S.-based company is trying to "match supply with demand." Layoffs are to start in February and March. Mosaic has about 1,500 employees in Saskatchewan.

The layoffs come just a week after the company posted a jump in quarterly profit, but warned that it would cut output and that it expects weak results for its current quarter.

Mosaic shares fell $4.23, or 10.9 percent, to close at $34.56 on the New York Stock Exchange on Monday. (Reporting by Wojtek Dabrowski; editing by Peter Galloway)