Producers Norman Lear and Jerry Perenchio said yesterday they have agreed temporarily to suspend their effort to acquire stock from Michigan residents who own shares of the Detroit-based Evening News Association. Lear and Perenchio agreed to suspend their stock solicitation in return for a promise from the Michigan attorney general's office that the state will not enforce a tough antitakeover statute until the U.S. Court of Appeals for the 6th Circuit rules on its legality. Lear and Perenchio said hearings in the appeals court will begin on Aug. 20.

Evening News recently became the target of a $453 million hostile takeover bid from the producers.

Lear and Perenchio also said yesterday that U.S. antitrust regulators have terminated the 15-day waiting period applicable to its $1,000-a-share tender offer. GM to Modernize Auto Plant in Indiana General Motors Corp. yesterday announced a $575 million modernization program at its Chevrolet-Pontiac-Canada Group plant in Marion, Ind.

Four General Motors plants are expected to be chosen for large-scale modernization programs, which include installation of the latest in presses and other equipment, said Mark White, director of personnel at the Marion plant. Marion's sister plant in Mansfield, Ohio, was named as the first July 3.