The Senate Foreign Relations Committee was assured yesterday by Secretary of State Cyrus R. Vance that he would not present an American peace plan for the Middle East during his trip to Israel and Egypt this weekend, Senate sources reported.

Announcing the Egypt, would not resume negotiations with Israel unless the Israelis made substantial concessions, Egyptian President Anwar Sadat said Sunday that only a new American peace proposal could break the stalemate that has developed in his 8-month-old peace initiative.

Vance faced critical questioning at the closed-door session from Senate committee members who have traditionally supported Israel and who evidently fear that the Carter administration may be preparing to respond to Sadat's plea.

The secretary reportedly did keep an option to present specific American proposals "to bridge differences" if direct negotiations can be resumed later as a result of his trip.

The two-hour session, which was devoted about equally to the Middle East an strategic arms limitation talks (SALT) with the Soviet Union, also covered these points, according to Senate sources.

Saudi Arabia has indicated that it would prefer to see the Sadat initiative, which began with the Egyptian president's trip to Jerusalem last November, shelved and a new broader peace move begun. Vance reportedly portrayed the new Saudi opposition, other Arab opposition and new internal problems for Sadat, as key factors in Sunday's renunciation of direct talks.

Vance denied that the administration would hold back submitting a new SALT agreement with the Soviets because of this year's congressional elections. "The treaty will be signed when it is ready to be signed," the secretary was quoted as saying.

Committee members were skeptical in their questioning of a Pentagon plan to reduce the vulnerability of the American intercontinental ballistic missile force by constructing 10 to 20 concrete holes for each U.S. missile. This would confuse Soviet targeting. The multiple aim point concept received what listeners thought was only a lukewarm defense from Vance. He emphasized that it was only one of several options under discussion.

Leading the questioning of Vance on the Middle East were Sens. Frank Church (D-Idaho), Richard Stone (D-Fla), Jacob Javits (R-N.Y.) and Clifford Case (R-N.J.), all of whom are strong supporters of Israel.

Senate and State Department sources reported signs of a campaign to focus criticism on Saudi Arabia for the Middle East stalemate. This theme emerged in yesterdays questioning of Vance, and is also contained in a draft letter being circulated among some senators.

The administration argued successfully earlier this year that the Senate should approve the sale of 60 F15 fighter-bombers to Saudi Arabia to help ensure continued Saudi moderation and influence on peace prospects. The draft letter reportedly expresses support for renewed face-to-face negotiations between Egypt and Israel, and asks supporters of the F15 sale to press the Saudis to exercise "moderation" now.