The talks to be held this weekend by representatives of Egypt, Israel and the United States are only exploratory and there is no sign so far of any breakthrough that could lead to an early conclusion of a peace treaty, authoritative Egyptian officials said today.

At the same time, President Anwar Sadat accused Israel of "wagging a deliberate campaign to distort the facts" about the negotiations and pledged that he would never accept a treaty that give Israel special "privileges" in its relations with Egypt.

Referring to an article in the draft treaty worked out in the Washington talks last month that would put Egypt's treaty obligations to Israel ahead of its obligations to other countries. Sadat said.

"We offer peace. But Israel wants to have a privileged position. Never, I am sorry. No. Neither over our Arab brothers nor any other state."

Dr. Osama el Baz, first undersecretary at the Foreign Ministry who will accompany Prime Minister Mustapha Khalil to the Brussels meeting with Secretary of State Cyrus Vance and Israeli Foreign Minister Moshe Dayan, said the Egyptians "have no idea how soon the real negotiations will start.

"If the Israelis are flexible, we are willing to resume right away," he said. "But if they remain negative about the West Bank and Gaza, if they insist on the treaty as it stands giving up obligations, there is no sense resuming. It's a nonstarter."

What the Brussels talks would determine, he said, was whether there was any reason to think Israel is willing to reconsider its position on any of the remaining issues since the failure of Vance's Middle East mission a week ago.

"We are going to Brussels to see if any change has taken place or is likely to take place in the immediate future," he said. "We are testing. We don't want another round of frustration and a further erosion of good will."

Other Egyptian officials not directly involved in the negotiations admitted they were taken by surprise at the announcement of the Brussels conference. They said they doubted that Vance would have called the meeting if he did not have some indication that the Israelis were prepared to reconsider their position on some points.

They were intrigued by Dayan's remarks before the Israeli parliament on Tuesday. Dayan reportedly said Israel was willing to undertake new discussions on the proposed letters linking an Israeli-Egyptian peace treaty with automomy for the Palestinians in the West Bank and Gaza and the idea that the security measures prescribed in the draft treaty be reviewed after a certain time.

Egypt still views the proposed treaty not as an end in itself but as a step in a process that will inevitably lead to the end of Israel's presence in the occupied territories, and the establsihment of some structure by which the Palestinians there could determine their own future. Israel is not prepared to go that far, and disagree with Egypt's interpretation of the Camp David agreements.

The latest round of Palestinian attacks inside Israel is seen here as fortifying Israeli determination to maintain a military presence in the occupied territories and to resist full automomy for the Palestinians.

In the Egyptian view, that is a shortsighted approach by the Israelis. Sadat denied Begin's accusation that Egypt had made new demands in the late stages of the negotiations. He said Egypt's position has been consistent since he went to Jerusalem more than a year ago. "We didi not introduce new elements," he said.

Sadat spoke angrily about Begin's comments in the Knesset, but he also said that "peace is inevitable, God willing." In that, he reflected what seems to be the prevailing attitude here as the peace talks limp ahead to an uncertain conclusion.

The Egyptians are annoyed at Israel, and concede that the good will prevailing at Camp David and at the time of Sadat's trip to Jerusalem has been eroded. But they also cling to the belief that the peace process is irreversible, and that Israel must eventually recognize what the Egyptians see as the historic inevitability of a transfer of authority in the West Bank and Gaza to the people who live there-the Palestinians.