The Firestone Tire & Rubber Co. is selling a line of imported steel-belted radial tires that are defective and should be recalled, the Center for Auto Safety charged yesterday.

The consumer group, which triggered the recall of millions of Firestone 500 steel-belted tires, alleged that the Firestone Cavallino tire is as dangerous as the 500. The group called on the government to investigate.

A Firestone spokesman denied the charge, saying, "The performance record of this tire in both Europe and the U.S. does not justify an investigation." The tire is built both in the U.S. and Italy for imported cars.

In letters to Joan Claybrook, head of the National Highway Traffic Administration, and to Jay W. Furness, England's transportation safety director, the center's executive director, Clarence Ditlow, claimed that Cavallino tires had a higher adjustment (failure) rate than certain models of the 500.

In its own informal survey, the consumer center found Cavallino tires made both in Italy and the U.S. on sale in Washington area stores.

In the letter to Claybrook, the center said "the need for an expedited investigation is all the more apparent in view of Firestone's pending sale of Cavallino steel-belted radials in at least the Washington metropolitan area." The group noted two recent ads in The Washington Post and The Washington Star as evidence of tire sales.

In a letter to British authorities, Ditlow called for a cooperative effort by the transportation agencies of several countries to protect consumers "from callous multinational corporations like Firestone which are concerned only with making profits."

The Firestone spokesman called the center's action "harassment," and said the failure rate of the Cavallino was far below that of the 500 tires.

That recall was voluntary and was the result of negotiations between the company and the Transportation Department.