President Anwar Sadat announced today that China has agreed to supply weapons to Egypt, a surpise that gives him an important political boost and brings China for the first time into the mulit-billion-dollar Middle East arms bazzar.

Sadat gave no details of the deal, but Western sources here told reporters that it involves sale by China of several squadrons of Mig 19 jet fighters, possibly as many as 60 planes.

The Mig 19 is an old plane, designed by the Soviet Union. The Chinese have been building it since the early 1960s. Its acquistions would have meant little to an Egypt at war with Israel but it could be useful asset to restructuring its armed forces for a different kind of mission in the Red Sea region and in Africa.

In his annual speech to troops stationed in the area of the Suez Canal, which Egypt reopened four years ago today, Sadat said he also was planning to ask the United States for permission to manufacture sophisticated U.S. weapons here under license.

The United States suddenly has emerged as an important arms supplier to Egypt, one of Sadat's major successes in his policy of negotiating peace with Israel, but it is not clear whether Sadat discussed this proposal with a Pentagon survey team that was here recently to assess Egypt's military needs.

[State Department spokesman Hodding Carter said in Washington that several U.S. weapons manufacturers have made proposals for coproduction projects with Egypt, but that the only one approved so far is for radio equpement. Carter said decisions on the other proposals would be made on a case-by-case basis after further examination.]

If licenses to make American weapons are granted, the work presumably would be done in the factories set up over the past three years by the Arab Organization for Industrialization, a weapons-manufacturing consortium of Egypt, Saudi Arabia, Qatar and the United Arab Emirates. That orgaization broke up last month when the three oil states pulled out to protest the Egyptian-Israeli peace treaty.

Sadat said the organization would continue in new form as the Egyptian Organization for Military Industrialization. The reconditioned factories still exist, the Egyptian workers have trained and the manufacturer of jeeps under an agreement with American Motors Corp. continues.

China is short of modern, sophiticated weapons and has not been among the participants in the rush to supply arms to the Middle East countries. But Peking developed a military supply relationship with Egypt in 1976, when China agreed to send some spare parts for Egypt's Soviet-supplied weapons after Sadat broke with the Soviet Union and the Kremin imposed an arms embargo.

Little had been heard from the Chinese since, and there was no advance indication of an important arms deal in the making.

"It gives one great pleasure," Sadat told the cheering troops today, "to announce that China has concluded a deal with us." He said he had "nothing to do but to express in your name our thanks to the leadership of China for this deal which is devoid of ulterior motive.

There was no announcement or comment from Chinese officials.

The spare parts the Chinese supplied three years ago were free, but Egypt is apparently going to have to pay for the planes. With its hard currency position much improved over the past three years, Egypt could pay cash if necessary, but the Egyptians would probably prefer a barter arrangement.

When the Soviet Union cut off shipments of weapons and spare parts to Egypt after the 1973 Middle East war, Sadat made a virtue of necessity an proclaimed a policy of diversifying the country's sources of weapons.

Egypt has acquired Mirage fighterbombers from France and French and British helicopters. But the heart of the air fleet is the Soviet-supplied Mig 17s and Mig 21s, which are aging and parts. Egypt also urgently needs replacements for its tanks and air defense missiles, also Soviet-suppled.

The United States has already agreed to send 50 F5 fighters, although the Saudis have apparently backed out of a commitment to pay for them and Sadat is vague about where he will get the necessary $525 million. The United States also agreed to supply an unspecified number of F4 Phantoms. Sadat has promised that the first of the Phantoms will be on display at the annual military parade in October.

Egypt's defense minister, Gen. Kamal Hassan Aly, has said that with the end of the struggle against Israel, Egypt is going to retrain and reorganize its armed forces for a new mission.

This is understood to mean the development of smaller, mobile units that Egypt can use to protect its friends and chastise or intimidate its foes in Africa and the Red Sea region, none of which can match Egypt in military strength.

But it is axiomatic here that this program must be accompanied by an influx of weaponry that will keep the armed forces satisfied and politically content. With the Arab arms organization dissolved, the F5 deal up in the air, Phantoms still in the talking stage and no new tanks in sight, Egypt's arms acquisition campaign was faltering.

For that reason, the Chinese arms deal comes at a propitious moment for Sadat.

Meanwhile, Israeli Foreign Minister Moshe Dayan, who arrived here yesterday on a three-day visit, went to Luxor to view ancient Egyptian sites before resuming talks later this week with Egyptian officials on details of normalization such as border crossings, visas and air traffic.

Egyptian sources said last night that Egyptian intends to keep the border at El Arish closed and had turned down Dayan's request that Egyptians from El Arish be permitted to work in Israel and Israeli fishermen be allowed to fish in Egyptians waters. Egypt is prepared to allow some travel by air and sea between the two countries but only for specifec purposes and with advance approval, the sources said.

Israel would like to accelerate the pace of normalization, but the real differences remaining between the two countries are over the future of the occupied territories. Those issues were not on Dayan's agenda.