President Reagan, in a last-minute bid to avert an embarrassing foreign policy defeat in Congress, yesterday withdrew the proposed sale of shoulder-fired Stinger antiaircraft missiles from his military aid package to Saudi Arabia.

By pulling back on the Stinger missiles, Reagan hopes to prevent Congress from blocking the sale. The White House has calculated that by removing the most controversial weapon in the package, it may have mustered sufficient support to outmaneuver opponents of the sale.

Reagan plans today to veto congressional resolutions passed blocking the sale, White House officials said. The Stinger concession was made in an attempt to persuade enough senators to change their stance and allow the presidential veto to stand, and the sale to go through. By administration estimates, 11 senators would have to change their votes.

Top administration officials continued to lobby senators last night. White House officials said if enough votes are assured, the president would probably issue his veto early today and seek a quick Senate vote. However, if Reagan is still short of votes, he may issue the veto closer to its midnight deadline, which would postpone Senate action until after the Memorial Day recess.

Congressional opposition to the sale forced the administration initially to reduce drastically a Saudi request for a multibillion-dollar arms package, including modern jet warplanes, to the $354 million sale that was finally proposed. Removal of the Stinger missiles from the package would reduce it further, to about $250 million, according to Senate Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.).

Presidential spokesman Larry Speakes said last night that the decision to drop the Stingers resulted in "substantial progress" toward sustaining the veto, but he said Reagan was still short of the 34 votes required to sustain it if all senators are present.

Congressional leaders also reported that Reagan's gambit had improved the outlook for the sale.

Saudi Ambassador Prince Bandar bin Sultan said he delivered a message to Reagan yesterday from King Fahd giving his approval for eliminating the 600 Stinger missiles and 200 launchers from the aid request. Some members of Congress claimed that the portable missiles could easily fall into the hands of terrorists and be used against American or Israeli targets.

White House officials said the decision to drop the Stingers came after Reagan's legislative strategists concluded that there was no other way he could win congressional approval. White House aides consulted Monday with the Saudis and Bandar discussed the proposal at the White House twice yesterday -- once with Reagan and top advisers, and later with national security affairs adviser John M. Poindexter.

Withdrawal of the Stingers leaves 1,666 air-to-air Sidewinder missiles and 100 antiship Harpoon missiles in Reagan's proposal. Reagan is expected to send the Senate a letter outlining his decision to drop the Stingers.

Secretary of State George P. Shultz explained the proposal to salvage the Saudi arms sale during an hour-long luncheon meeting with Senate Republicans. Shultz, according to participants, depicted the plan to remove the Stinger missiles from the package as a Saudi initiative and stressed the importance of approving even a scaled-down arms package as a political signal of continued U.S. support for the Saudi government.

Sen. Alan Cranston (D-Calif.), who led Senate opposition to the sale, conceded that removal of the Stingers from the package strengthened the administration's position. "The White House faced inevitable defeat with a full package," he said. "This makes it tougher to override a veto."

Cranston said that before Shultz's announcement, the administration was about six votes short of the 34 necessary to sustain a veto. Others agreed. "The momentum is now in the direction of supporting the president," said Sen. John W. Warner (R-Va.), who noted that Shultz received a standing ovation after his sales pitch.

Meanwhile, Lugar said even a scaled-down arms package "is worth a great deal. It is an affirmation of our willingness to come to their assistance."

Lugar quoted Shultz as saying that the Saudis have been promised the Sidewinder and Harpoon missiles before the first scheduled delivery date around 1989 if they need the extra missiles for defense.

Also yesterday, Reagan met privately with a group of Jews from around the country to explain why he thinks the sale should be approved. Some senators have expressed concern about criticism from the Jewish community if they support the sale. A spokesman for the American Jewish Committee called the meeting "ill-advised."

But a participant, Ivan Boesky of New York, said in a statement afterward that Reagan has worked for peace in the Middle East and "should be supported" in the Saudi arms sale. A vote for the proposal, he said, "is not a vote to destroy Israel."