Officials of American Telephone & Telegraph Co., after years of urging congressional action on telecommunications issues, yesterday attacked legislation before a House subcommittee as anticompetitive and a threat to the nation's ability to compete in world markets.

The criticism, the most strident testimony from company officials in recent memory, focused on legislation sponsored by Rep. Timothy Wirth (D-Colo.), chairman of a House telecommunications subcommittee. Wirth's subcommittee is in the midst of lengthy hearings on the legislation and the AT&T antitrust settlement.

Instead of passing a bill while a federal judge is evaluating the terms of the antitrust settlement between the Justice Department and AT&T, Congress should await the breakup of AT&T, company officials said.

The divestiture could take as long as two years, and AT&T Executive Vice President Morris Tanenbaum cautioned against "precipitous actions" until it is clear how the decree is working. "The judicial process should be allowed to work," he said.

Tanenbaum charged that Wirth's bill "imposes the most restrictive array of limitations on the Bell System that have yet to be advanced" and would make it nearly impossible for AT&T to compete in either the nation's financial or technical marketplaces.

"The mishmash of punitive and regulatory measures throughout H.R. 5158 Wirth's bill will harm ratepayers, deny consumers the benefits of innovative technology, restrain competition and diminish U.S. pre-eminence in telecommunications at home and abroad," Tanenbaum said.

The AT&T testimony came as Wirth, in a subsequent speech to state regulators, reiterated his support for rapid legislative action. Wirth said he hopes to move the bill through the Commerce Committee and to the House floor within two months.

At the hearing, Wirth said he was dumbfounded at the AT&T testimony, noting that he had not received that feedback from AT&T Washington representatives.

"I am at a loss to understand either the virulence of the testimony or why at least some within AT&T have altered their position and now believe the courts and not the Congress should set telecommunications policy," Wirth said later.

In particular, Tanenbaum, who testified before the subcommittee with top Bell System financial and technical officials, was critical of provisions of Wirth's bill that require AT&T to set up separate subsidiaries to get into competitive businesses, bar sharing of information among AT&T branches and prohibit the company from controlling the information sent over its long distance lines, the key piece of the AT&T network that the company retains under the settlement.

The Jan. 8 settlement ended a lengthy antitrust suit against the company.