The future of the United Auto Workers (UAW)likely depends on whether it can unionize factories in the United States run mainly by Asian carmakers, the group's president said on Sunday.

In an escalation of his rhetoric on the issue, Bob King told the opening of the UAW's legislative conference that companies such as Toyota Motor Corp <7203.T> , Nissan Motor Co <7201.T> and Honda Motor Co Ltd <7267.T> don't fear us.

He said the union must aggressively reverse its decades-long slide in membership and its gradual loss of power if it is to survive.

The UAW believes that without organizing overseas Asian and European companies it can no longer safeguard pay for U.S. auto workers.

If we don't organize the transnationals, I don't think there is a long-term future for the UAW, King said.

Membership at the UAW, which represents workers at all three Detroit automakers, is down to about 400,000 active workers and another 600,000 retirees.

The UAW has never successfully organized a major U.S. auto factory apart from those run by General Motors Co , Ford Motor Co , and Chrysler, which is now under management control of Fiat SpA .

A push to organize Toyota's Georgetown, Kentucky, plant in 2007 fizzled. Another attempt at Nissan's Tennessee plant also failed.

King hopes to have one successful organizing drive in 2011, but he would not disclose where the union would start its campaign.

We're weighing a number of factors and deciding which one we will focus on first, King said, adding that he hopes to make an announcement within 90 days.

Overseas automakers have established their U.S. presence mainly in the non-union South.

Japan's Toyota, Nissan, and Honda and Korea's Hyundai Motor Co <005380.KS> and Kia Motors <000270.KS> have extensive U.S. manufacturing facilities. Germany's Volkswagen is building a plant in the United States.

King said overseas manufacturers are good companies, and that the UAW would work with them to build their businesses.

We want to be on the cutting edge of labor relations, King said. That is the opportunity for all these companies.

The UAW negotiated steep concessions with Detroit manufacturers in 2009 as part of the deep restructuring of the industry that included bankruptcies at GM and Chrysler.

Asian auto brands represent nearly 50 percent of U.S. auto sales.

(Editing by Dhara Ranasinghe)