A delegation of Arab leaders is expected in Washington later this month to outline to President Reagan decisions reached at last month's Arab League summit meeting, State Department officials said today.

Secretary of State George P. Shultz and Moroccan Foreign Minister Mohammed Boucetta discussed the trip during a meeting here today. Morocco's King Hassan is expected to head the delegation.

The arrival of the delegation from Morocco, Saudi Arabia, Tunisia and Syria is widely viewed as signaling a new stage in the president's Mideast peace initiative.

"There are a great variety of plans on the table. Soon the stage of putting forward plans and positions will be over, and the stage of trying to find compromises and solutions will come to the fore," a senior administration official said today.

He was describing Shultz's view of the outcome of talks he has held here with several Arab foreign ministers in connection with the annual U.N. General Assembly session.

The official said the Arab leaders visiting Washington "want to be sure President Reagan understands what they put forward and also that they understand his proposal."

A second delegation of Arab leaders, including Jordan's King Hussein and Yasser Arafat of the Palestine Liberation Organization, is expected to visit Moscow and other capitals at the same time the Moroccan-led delegation is in Washington.

While focusing attention on the need for compromise on broader Mideast peace proposals, the senior official said he believes this process will be helped by a new realization that "the Palestinian problem has to be faced up to."

The official said that, "even with the problems of Lebanon," the peace process has been "very much on people's minds." But he later admitted that the administration still faces difficult bargaining to solve the crisis in Lebanon.

He said special envoy Philip C. Habib has found during his recent travels in Israel, Syria and Lebanon that there are still "plenty of problems" tied to withdrawal of foreign forces from Lebanon.

"Everyone agrees they will withdraw, but then there are all these conditions, and you try to untangle the conditions. . . . I wouldn't rule out a quick solution on getting the troops out," the official said.

Habib is to brief Reagan Wednesday on his recent talks. Reagan, asked at the White House yesterday if he expects an optimistic report, held up crossed fingers.

On relations with the Soviet Union, the official described the 7 1/2 hours of talks Shultz held with Soviet Foreign Minister Andrei Gromyko over the last week as reflecting the strained state of ties between the two superpowers. "There were many points of disagreement and tension; that's one thing we agree on," he said.

Although the subject of a summit meeting between Reagan and Soviet President Leonid I. Brezhnev did not come up at talks here, the official said the United States would welcome a meeting "if there were some constructive things that could emerge."

The official said the United States has reservations about Gromyko's proposal before the General Assembly for an end to nuclear tests because of continued questions on verification.