High Egyptian officials said today that Israel's rejection of a U.S.-Soviet deal on U.N. observers for the Sinai was not expected to hinder the turnover of a 2,00-square-mile swath of desert scheduled for Wednesday, the second phase of Israel's Sinai pullbacks. The Egyptians made it clear, however, that Cairo favors speedy implementation of the U.S.-Soviet proposal to replace a current 4,000-man U.N. force with an expanded version of the U.N. Truce Supervisory Organization they said that Egyptian policy remains firmly attached to a U.N. role in the Sinai. Some Epgyptian sources suggested Israeli motives in refusing the U.S.-Soviet deal included a desire to force acceptance of joint Israel-Egyptian patrols, keeping the United Nations out of the picture. Israel has long mistrusted the United Nations, saying that Soviet allies and other pro-Arab nations constitute an anti-Israeli majority. According to wire reports reaching here, Israeli Deputy Prime Minister Yagael Yadin said Israel's refusal was based on insistence that the international police force be armed to prevent treaty violations and that it take orders from the Security Council rather than the Secretary General. Secretary General U. Thant's removal of UN. truce supervisers in 1967 on a request from Egypt has been cited as a contributing factor to the breakout of the Six Day War shortly after. The approximately 150 U.N. truce supervisors from 16 nation are unarmed and operate under Secretary General Kurt Waldheim's authority without need of a Security Council mandate. They have been in the area since the 1948 war, supervising the truce that ended that conflict. The U.N. emergency forces, however, are armed and operate on a renewable Security Council mandate dating from 1974 and expiring July 24. The Soviet Union has said it will use its veto to block renewal of the mandate as a gesture of support for the Arab nations that oppose Egypt's peace treaty with Israel. Faced with the veto threat, the United States last week worked out with Moscow a compromise calling for expanding the truce supervising force to replace the emergency force and increasing its duties to include policing Israel's withdrawals in the Sinai. This permitted the Soviet Union to avoid formally voting on a Sinai force and being seen by its Arab allies as approving arrangements to carry out a treaty it opposes. Western diplomats here, noting the friendly atmosphere between President Anwar Sadat and Prime Minister Menachem Begin of Israel, conceded the international forces were not essential to this stage of Israeli withdrawals. Israel and Egypt carried out the El Arish handover in May without trouble, they recalled. But as the talks on Palestinian autonomy move closer to essential to prevent accusations from growing into serious disputes that could endanger the treaty, the said. In addition, the later stages of Israeli withdrawal involve more vital parcels of land, including the strategically valuable Gidi and Mitla passes in central Sinai and the Alama oil fields from which Israel is estimate to be pumping more than 30,000 barrels of oil a day. The land to be returned Wednesday includes valuable manganese mines and deposits of other commericial minerals. But it has no particular strategic value and contains only half a dozen exhausted oil wells that Egyptian oil industry officials said are no longer worth running. The turnover does, however, return unencumbered control of the access route to the nearby Abu Rudeis oil field, these sources said. Under the September 1975 partial withdrawal accord that returned Abu Rudeis to Egypt, Israel retained use of parts of the road to Abu Rudeis from Suez City at the head of the gulf. CAPTION: Picture, EPHRAIM EVRON ... Israel wants fully armed soldiers