Kenneth Hahn, Los Angeles County supervisor, is asking President Carter and the International Olympic Committee to hold this summer's Olympics in Los Angeles, and he says the United States should go ahead with the idea whether the IOC approves or not.

"We could put on a Spartan-like Games without any frills," Hahn told reporters today after disclosing he had sent telegrams suggesting the switch from Moscow to Los Angeles to both Carter and the IOC.

"We made a little study this week to determine if we could handle it if the IOC would authorize the transfer of the 1980 Games," he said.

If the IOC insists on holding the Games in Moscow, he added, Los Angeles could be used as the site for an alternative Olympics for those countries boycotting.

Insteading of calling it the Olympic Games, we could call it the Spartan Games and hold it in true Spartan style without any frills or commercialism," he said.

Los Angeles has been designed as the site of the 1984 Olympics, winning the bid partially on a promise to put on a no-frills competition primarily in facilities already constructed. They include the Coliseum, the main stadium used in the 1932 Olympics. Hahn said he thought a Los Angeles Olympics might find widespread acceptance, and said there should be no restriction on countries who want to complete.

Meanwhile Minority Leader Howard Baker offered to sponsor legislation to provide finacial support for a Free World Olympics to be held in Puerto Rico if the U.S. Olympic Committee decides that is an appropriate site.

In a letter to Robert J. Kane, USOC president, Baker said he had discussed the proposal with Puerto Rico Gov. Carlos Romero-barcelo, who said the event would be "well received" by Puerto Ricans.

He said Puerto Ricans have experience at putting on such events because they held the Pan American Games last Year.