United Auto Workers president Bob King has said he was "upbeat" about reaching a contract deal with US automakers that would keep them competitive against Asian and European rivals.

"I'm upbeat because there is a real commitment to keep the companies successful," King said.

King, speaking to Reuters after a speech to the Detroit Economic Club, said it would be difficult to reach a deal with General Motors, Ford and Chrysler Group before the current four-year contracts expire on 14 September.

He said that while the UAW has no "sacred cows" in its bargaining proposals with the automakers, the union's priority was to win an agreement that would clear the way for second-tier workers making about US$14 per hour to move toward full wages of about twice that amount.

King said he would be disappointed if the talks did not end with a successful agreement at all three automakers.

The union only has the power to call a strike at Ford under terms of the USgovernment bailout of GM and Chrysler.

"I'll just feel like we can do better. I'll just feel like I haven't done what I wanted to do," King said when asked about the prospect of a strike or arbitration.

Most analysts have said they expect a quick resolution to the UAW contract talks, one that ends with some form of profit sharing rather than a traditional wage that would saddle the recovering companies with higher fixed costs.

King said he had told UAW workers to prepare for a profit-based bump in pay in order to keep the Detroit automakers competitive.

"The facts are that our companies face a lot of competition," he told Reuters.