A representative of the nation's mayors called yesterday for tough new federal laws limiting media ownership or setting strict common carrier regulation of the cable industry if cities lose much of their authority to regulate cable television.

Seattle Mayor Charles Royer, speaking on behalf of the National League of Cities and stepping up the bitter battle between city officials and the cable industry, urged a House subcommittee to maintain municipal regulation of cable television systems.

Calling cable a "natural monopoly, in some respects like a utility," Royer said that without municipal regulatory authority to provide access to cable systems to local citizens, "strict federal laws, eliminating the present pattern of cross-media and concentration ownership, must be passed."

Royer's comments came during a hearing of the House Telecommunications subcommittee called by its chairman, Rep. Timothy Wirth (D-Colo.), to "examine the role played by private entities which own and control the facilities used for electronic communication."

The hearing, however, served to magnify the tensions revolving around telecommunications legislation between municipal and cable interests and between American Telephone & Telegraph Co., which was represented by former Federal Communications Commission Chairman Newton Minow, and the newspaper industry.

Royer's testimony focused on the consequences of legislation now awaiting Senate floor action that would limit the local government role in regulating cable television. He was sharply challenged by Robert Ross, speaking for the National Cable Television Association, who said he found ironic a recommendation to continue municipal regulation of cable operators during a hearing called to discuss media diversity. "It's cable that's expanded diversity," he said.

Minow, meanwhile, used the forum to attack the American Newspaper Publishers Association argument that AT&T should not control both the line and the information that goes into the home. The Senate Commerce Committee, in sending the legislation to the full Senate, has, in essence, adopted that ANPA position in the bill.

"They've managed to take an economic protectionism argument and cloak it in the First Amendment," Minow said, noting that by wanting to bar AT&T from controlling, rather than just transmitting, information into the home, ANPA and its supporters were hoping to "shut up" AT&T. "If they're talking about the First Amendment, let's have everybody talk," Minow said.

Television producer Norman Lear warned the committee that the American people are watching too much television and that the product they view is guided by an overwhelming and inappropriate concern for profits.

The control of network television by the three major networks invites "homogeneous broadcasting that allows for too little diversity and retards the development of new and competing technologies," Lear said. "With the explosion of new technologies, this history, however, must not be repeated."

Lear, who also criticized the FCC's action last week urging Congress to repeal equal time regulation and the Fairness Doctrine, said that regulation is probably required to maintain diversity in broadcasting. "If it requires regulation to guarantee access to the diverse voices in our land - this child of television would urge you to supply it," Lear said.