The editor of USA Today yesterday called worries about concentration of newspaper ownership "obsolete" because of increasing competition from other media, but the head of the Newspaper Guild warned that news monopolies are still a danger.

"The First Amendment is meant to encourage a multiplicity of voices, not to concentrate the loudest ones in one or two hands," said Charles A. Perlik Jr., president of the guild, a union representing newspaper reporters, editors and other employes.

Perlik squared off against John C. Quinn, executive vice president of Gannett Co. Inc. and editor of USA Today, at a panel discussion on group ownership of newspapers sponsored by the American Enterprise Institute, a Washington-based think tank.

Joining Perlik and Quinn on the panel were Rob Small, president of the Moline (Ill.) Daily Dispatch, one of seven papers owned by Small's family under the banner of the Small Newspaper Group, and Bruce A. Wright, administrative assistant to Rep. Morris K. Udall (D-Ariz.) and a specialist on media-concentration legislation.

Seventy percent of the nation's 1,700 daily newspapers are owned by newspaper groups. Panel moderator Nick Thimmesch, the institute's resident journalist, noted in his opening remarks that "there is a blue-sky prediction that by the year 2000 there will only be a handful of independent newspapers."

Quinn defended group ownership, saying that it offers economies of scale, pooling of resources, information and expertise, and other advantages that might not be available to independent newspapers.