The Carter administration has privately expressed strong concern about the continuing political executions in Iran to that country's religious leadership, the U.S. ambassador-designate to Iran said yesterday.

The envoy, Walter L. Cutler, said that the expressions of concern had been made through "a variety of channels" that he would not describe in a public session of the Senate Foreign Relations Committee.

Administration officials said after the hearing that U.S. diplomats in Iran still have not been in direct contact with Ayatollah Ruhollah Khomeini, the Islamic leader who "supervises" the revolutionary government from the holy city of Qom.

The administration shunned all contact with Khomeini while the Islamic fundamentalist was leading the year long political revolt that drove Shah Mohammad Reza Pahlavi into exile in January, but may be talking to Khomeini directly now.

Cutler, a career diplomat who spent the last three years as ambassador to the African nation of Zaire, and Alfred L. Atherton Jr., the State Department's top expert on Arab-Israeli negotiations who is now ambassador-designate to Egypt, testified yesterday before the Senate panel, which unanimously recommended approval of the two nominations by the Senate.

Senators competed in praising Atherton for his career record of attempting to bridge the gap between Arabs and Israelis. Sen. Charles H. Percy (R-Ill.) said Atherton's "low-key, rational approach is just what is needed" in making sure the Egyptian-Israeli peace treaty works.

Atherton acknowledged that Saudi Arabia's offer to pay $535 million for 50 F5E jet fighters Egypt wants to buy from the United States is now "in doubt," but he said the three countries are still talking about the deal.

Cutler was pressed by several committee members on the administration's decision to discourage the shah, now in the Bahamas, from coming to the United States.

Sen. Claiborne Pell (D-R-I.) appealed to the White House "not to give the shah a cold shoulder in his time of need." Percy cited former secretary of state Henry A. Kissinger's "strong feeling that we should not turn our back on a 28-year ally."

Maintaining that the shah is welcome here "in principle," Cutler said the administration has to take into consideration "questions of timings and security," and has to review how the shah's arrival here "would impact on our national interest and in Iran."

The execution of a Jewish businessman last week was the main topic of questioning by several senators. Cutler said that it "was not clear that the execution was a result of any one charge, such as supporting Zionism," as reported in some press accounts.

He said that after U.S. questions were put to the Iranian authorities about the case, new pledges of protection of all minorities in Iran, including Jews, had been made. utler left several members of the committee with the impression that the administration is actively considering establishing a 100,000-man, highly mobile strike force for use in the Persian Gulf. Asked about press reports of planning for such a force, Cutler said, "There is a place in our diplomacy for a military presence. The decision has to be very carefully considered."