Delegates to an Arab League conference, designed to open a dialogue with Washington over Israeli settlements in the occupied West Bank, expressed disappointment and anger yesterday that no Reagan administration official agreed to address it.

Participants in the meeting, which ended yesterday, were particularly upset that Secretary of State George P. Shultz chose the American Israel Public Affairs Committee (AIPAC) to make his plea for more Arab support for peace moves led by Jordan and Egypt.

"Shultz apologized, but they did not designate anyone else to attend, either," said Clovis Maksoud, the Arab League representative in Washington, who called the situation "a missed opportunity."

"We're not on the same wavelengths in our priorities," he said. "Maybe they feel they don't need it [an opportunity] at this point."

A State Department spokesman said, however, that the invitation to Shultz had come "very late" and "his schedule was all tied up."

"They made no effort to discuss the possibility of a replacement," he said, adding that the organizers also had made no attempt to coordinate the conference with the State Department.

The lack of communication over the Shultz invitation appeared symbolic of what emerged as the conference's central problem -- getting anyone in Washington to listen to the Arab viewpoint on the settlements, widely regarded on the Arab side as a key obstacle in any U.S. or moderate Arab bid to get peace talks going again.

The conference, the first ever held by the Arab League on the Middle East peace issue here, received scarcely any news media attention, something that also did not go unnoticed during the three-day affair.

Other than an appearance of a pro-Palestinian British film actress, Vanessa Redgrave, on ABC-TV's "Nightline" and of a group led by Nobel Peace Prize winner Sean MacBride on Metromedia's "Panorama" show, liitle notice was taken of the event.

Several speakers noted that while the site of the meeting, the Mayflower Hotel, was only a few blocks from the White House, the two were "light years" apart on the Middle East issue and moving daily further apart.

The conference, which reportedly cost the Arab League about $250,000, brought together a large number of well-known Arab, American and European scholars, politicians and statesmen. Among them were the noted French sociologist, Jacques Berque; Britain's U.N. ambassador at the time of the 1967 Arab-Israeli war, Lord Caradon; Austria's former chancellor, Bruno Kreisky, and the Arab League's secretary-general, Chedli Klibi.

Dean Brown, president of the Washington-based Middle East Institute, closed the conference by calling on the Reagan administration to begin its efforts to revive the Middle East peace process with "direct negotiations" between Washington and Tel Aviv to see what the two governments still have in common before pushing a similar policy of direct talks between the Arabs and Israel.

"The United States and Israel have to have a better understanding of where they are going in the long run," he said. "Without that, there is no hope of an effective U.S. role."

Brown said that the Arab governments and the Palestinians are badly in need of "direct negotiations" among themselves about where they stand today on various peace initiatives. Otherwise, he warned, the Arab peace plan adopted at Fez, Morocco, in September 1982 is heading for the same "historic grave" as President Reagan's Middle East peace initiative set forth then.