Despite testimony charging a political payoff, the Senate Foreign Relations Committee yesterday approved the nomination of Ohio real estate developer Marvin L. Warner to be ambassador to Switzerland without asking him a single question.

Sen. John Glen (D-Ohio), who received $6,870 in campaign contributions from Warner or members of his family in the past four years, praised this "ideal appointment" for a man he had highly recommended to President Carter.

Sen. Howard Metzenbaum (D-Ohio), who received $9,000 in such campaign contributions, said "Marvin Warner is the best" and dismissed any suggestion that Warner's political support of Carter should be a negative factor in his consideration.

Committee chairman John Sparkman (D-Ala), who reportedly also pushed hard for Warner's nomination, said "he's been a supporter of mine too." However, no record of Warner contributions to Sparkman was immediately available.

A native of Alabama, Warner has credited Sparkman - then chairman of the Senate Housing Committee - with helping launch his highly successful career as a housing developer by cutting red tape.

Yesterday Sparkman called Warner "one of the greatest home builders in the United States."

In a sworn statement filed with the committee, Warner reported that he or members of his family had contributed $66,000 to political campaigns since January, 1973, including $2,265 to the Carter campaign and $19,130 to the Democratic National Committee, of which Warner is a member. Sens. Frank Church (D-Idaho), and Richard Stone (D-Fla.), also members of the Foreign Relations Committee, were among senators listed as receiving contributions.

Warner is credited with arranging a 1976 fund-raising breakfast for Carter in Cincinnati that raised nearly $20,000 after expenses, and with helping line up political support for Carter in the Ohio primary. Carter stayed overnight in Warner's apartment while campaigning in Cincinnati.

Dennis Kux, a career State Department official appearing on behalf of the American Foreign Service Association, said there is "little evidence" that Warner is qualified to replace a career diplomat, Nathaniel Davis, as the ambassador to Switzerland. Kux testified that "an examination of Mr. Warner's background suggests that the appointment is a reward for political support and for substantial financial contributions."

In a hearing lasting less than 15 minutes, committee members asked no questions of either Kux or Warner.

The Cincinnati Post has quoted an Ohio Democratic official as saying that Warner was interested only an ambassadorship to "a big money market country." The paper said Glenn and Metzenbaum pushed a diplomatic job for Warner and Ohio Democratic Chairman Paul Tipps flew to Plains, Ga., during the presidential transition period to see Carter on Warner's behalf.

Warner first sought to be ambassador to the United Nations and then ambassador to Britain, according to reports. He was said to be delighted with the nomination to Switzerland, a major financial center. However, he has already asked the State Department how often he will be permitted to fly home, sources said.

Sparkman said he was told Warner that Switzerland is "one of the most delightful countries in the world," and that "he'd be right there for his secret number," presumably referring to a secret Swiss bank account. The Foreign Relations chairman, who may retire from Congress soon, told Warner, "I may be coming to see you some day."

SEN. Clifford Case (N.J.) the only Republican at the sparsely attended hearing, told Warner "you couldn't come under better auspices" and "I don't think there are any questions - there better hadn't be."

The committee also had no questions for Herbert Salzman, director of the Overseas Private Investment Corp. a federal agency, who has been nominated as U.S. representative to the Organization for Economic Coperation and Development. Sen. Abraham Ribicoff (D-Conn.), who introduced Salzman, called him "one of my best and most intimate friends" and said they live on the same floor of a Washington apartment building. CAPTION: Picture, SEN. JOHN GLENN . . . $6,870 from "ideal" nominee