Dozens of business and community groups yesterday urged the Port Authority and the leaders of its drivers union to work for "a responsible settlement" in the current labor dispute that threatens to disrupt service Dec. 1.

Specifically, they suggested that a fact finder's report issued in August become the basis for a new contract with Local 85, Amalgamated Transit Union, because it represents "a workable compromise."

The request to settle the impasse and avoid a transit crisis came from 43 sources, including the Greater Pittsburgh Chamber of Commerce, an affiliate of the Allegheny Conference on Community Development; Sustainable Pittsburgh; the African American Chamber of Commerce; and the Pittsburgh Partnership for Neighborhood Development.

The authority's board accepted the fact finder's report, but the 20-member executive board of the Amalgamated Transit Union's Local 85 rejected it.

Because the fact finder's report was rejected by the union and further negotiations proved fruitless, the authority board has voted to impose its "last and final" contract as of Dec. 1. That could lead to a work stoppage that management has said would constitute a strike but the union has said would be a lockout and illegal.

In case of a service shutdown that would affect people accounting for 240,000 bus and trolley rides a day, the groups yesterday introduced a Web site, keeppittsburghmoving.com, that will provide information and resources to help people get around.