For better or for worse, depending on which side of the line you are standing on, Mazda has confirmed rumors that it will stop building the Mazda6 at the AutoAlliance International (AAI) plant in Michigan, which it runs jointly with Ford, after the mid-size sedan's current cycle ends.

The company said the Mazda6's replacement for the North American market will be produced at its Hofu Plant in Yamaguchi prefecture, Japan, adding that the decision was driven by the firm’s “ongoing efforts to increase global manufacturing efficiencies”.

“Our intention is to transfer production of our next CD-car for North America from AAI and consolidate it at Hofu in order to improve production and investment efficiencies and optimize our business," said Takashi Yamanouchi, President and CEO of Mazda Motor Co.

Mazda established the AAI plant in 1985 but it became a 50-50 joint venture between the Japanese automaker and Ford Motor Company in 1992, when the name was changed to AutoAlliance International, Inc. Over the years, the facility has churned out more than 1.7 million Mazda vehicles, including the MX-6, 626 and from 2002, the Mazda6 of which over 500,000 units have been built. The factory also produces the Ford Mustang.

The Japanese automaker said it will continue to work with its former owner Ford, but didn’t go into any specific details.

“We are committed to working with Ford, our joint venture partner in AAI, to identify potential future opportunities for the plant,” said Yamanouchi. “Mazda and Ford have enjoyed a close relationship for over 30 years. We have collaborated on projects where there are mutual benefits, and both companies remain committed to continuing this strategic partnership."

Ford has not yet commented on Mazda’s decision to abandon the joint venture factory in Michigan.

Mazda and Subaru may soon be forced to axe two of their models in the US market, the Mazda6 mid-size vehicle and the Subaru Tribeca SUV, due to low volumes that undermine the efficiency of the U.S. plants that they are built in, according to a newspaper report from Japan’s business daily Nikkan Kogyo. It should be noted though that spokesmen for both companies declined to comment on the report.

Nikkan Kogyo wrote that Mazda is planning to discontinue production of the Mazda6 at the Flat Rock, Michigan plant, which it operates as a joint venture together with Ford Motor Co., as sales missed expectations. When Mazda introduce the latest generation of the mid-size model in 2008, the company expected an annual production of around 100,000 units, but last year, the plant churned out just 45,168 Mazda6s. In April, Mazda6 posted an increase of 7.8 percent but sales reached just 2,734 vehicles.

But being that the mid size segment is an important category, the report says that Mazda is mulling other options including the introduction of another model or build a similar vehicle at a lower cost factory in Mexico.

As for the Tribeca, which has been in production since 2005 at Subaru’s Indiana plant, the Japanese newspaper said the company has stopped the development of a new version and plans to use the increased capacity to build the better selling Outback and Legacy. This year through April, Subaru sold just 910 examples of the SUV model.

Source Nikkan Kogyo via Autonews [Sub. Req.]