HIROSHIMA (Kyodo) Mazda Motor Corp. is considering suspending production of its cars at its U.S. joint venture with Ford Motor Co., as the operation has remained unprofitable for some time, company sources said Friday.

While halting production at the Michigan plant, the Hiroshima Prefecture-based automaker plans to reorganize its overseas operations, shifting manufacturing to Russia and other emerging economies, the sources said.

Mazda is studying a plan to transfer production of the Mazda6, called the Atenza here, to a factory in Japan in 2013 at the earliest, while keeping its stake in the U.S. venture, with an eye to possibly resuming production if market conditions improve, they said.

Ford will continue production at the plant run by AutoAlliance International Inc.

The Michigan plant commenced mass production in 1987 as Mazda's first manufacturing base abroad. It became a joint operation with Ford when the U.S. automaker bought a 50 percent interest in the company in 1992.

Its annual output has fallen well below 200,000 vehicles, including cars produced by Ford, against the two firms' combined capacity to turn out 240,000 units.

While the U.S. operation falters, Mazda plans to begin assembling tens of thousands of vehicles per year in Russia by shipping components there in light of Moscow's plan to raise tariffs on imported cars, the sources said.

The company also intends to open a plant in Mexico with trading house Sumitomo Corp. as early as 2013, with the aim of raising annual output of small and other vehicles to 200,000 units in the future, according to the sources.