Japanese car maker Mazda says it has decided to stop building its mid-sized sedan at a plant in the United States jointly run with the Ford Motor Company.

A Mazda spokesman said Tuesday the decision to halt the Detroit production of the Mazda6 model was made after a recent reassessment of the company's global needs and demand in North America. He said the next generation of the car will be built at a plant in Japan's Yamaguchi prefecture. Mazda declined to say when the move will take place, or whether the Japanese firm will withdraw from its alliance with Ford.

Last week, the Nikkei business daily said Mazda would cease U.S. production of the model by 2013.

The Mazda-Ford plant in suburban Detroit employs more than 1,600 workers, and also makes the Ford Mustang.

The two companies formed a joint venture in 1992, when Ford took a 33 percent stake in the then struggling Japanese manufacturer. Ford now holds about 3.5 percent of Mazda's shares.