The United Auto Workers has said that it has reached a 'tentative', four-year contract agreement with DaimlerChrysler AG's Chrysler Group and will continue to negotiate with GM and Ford.

The previous contracts, negotiated in 1999, expired at midnight Sunday. Details of the tentative agreement with Chrysler weren't released, but UAW President Ron Gettelfinger said the deal contains what the union hopes to see in the other contracts. "This is the framework for the pattern agreement, absolutely," Gettelfinger said in remarks quoted by AP during a news briefing. Chrysler workers must still ratify the deal.

Ford and GM employees will report to work as usual while negotiations continue, Gettelfinger said. The UAW had hoped to reach simultaneous pacts with the Big Three, as well as auto suppliers Visteon and Delphi.

The negotiations come as the Big Three find themselves under pressure from a number of sources - including falling market share at home, negative pricing, rising costs and weak financial results.