The United Auto Workers, as part of an effort to broaden support among middle class Americans as it approaches bargaining with the three major U.S. automakers, on Thursday rallied at a downtown Detroit branch of the Bank of America

UAW President Bob King said the protest against the bank was part of the union's effort to increase its leverage with automakers by attracting support from those outside not only the UAW, but any union.

Major banks like Bank of America, the largest in the United States, don't pay their fair share of U.S. corporate taxes, King said, and fight rules to protect the middle-class taxpayers who bailed them out several years ago, King said.

The economy would be much stronger and our country would be much stronger if banks paid their fair share, King told about 100 UAW members inside while about 300 held signs on downtown Detroit streets.

We wouldn't be talking about cuts, said King. We'd be talking about creating good jobs.

Thursday's four-block march and rally was the culmination of a three-day UAW convention on broad UAW bargaining strategy for negotiations with General Motors Co, Ford Motor Co and Chrysler, which is managed by Fiat SpA.

Contracts with the three automakers expire on September 14 and official negotiations are expected to start in July or August.

UAW membership peaked at nearly 1.5 million in 1979 but is now under 400,000.

King during the three-day convention focused on the UAW's plans to connect with worker unions around the world and also to organize auto workers at U.S. plants owned by non-U.S. automakers like Toyota Motor Corp, Honda Motor Co, Hyundai Motor Co Nissan Motor Co and Volkswagen AG.

King said the UAW should be a major contributor to a wider defense of middle class pay and rights, a theme that has been a centerpiece of his presidency, which began last June.

We're not just fighting for our members, King told reporters on Thursday. We're fighting for everybody in the middle class.

(Reporting by Bernie Woodall; Editing by Gary Hill)

Michigan