Prime Minister Mustafa Khalil said today that chances are "rather good" that President Carter can wrap up a peace treaty between Egypt and Israel during his trip to the two countries.

Although he said Egypt is not yet committed to accepting the compromise submitted by Carter to the Israelis last weekend and "might introduce some changes," he described U.S. proposals as "very positive."

That was his original reaction when he was first briefed on the Carter proposals Monday, and nothing has happened since to diminish his optimism.

Khalil, who also is foreign minister and was Egypt's chief negotiator at the unsuccessful Camp David talks last month, was speaking to reporters after meeting with President Anwar Sadat to review the American proposals. They had been relayed Tuesday by national security adviser Zbigniew Brzezinski.

[Carter, in remarks as he left Washington Wednesday night, stressed the need for a comprehensive Middle East settlement, including not only Israel and Egypt but also other nations in the area. "Our negotiations are based on the idea that peace can only be achieved when we meet the legitimate needs of all who are affected by the conflict," he said.]

[Defense Secretary Harold Brown who last month toured the Middle East, was listed as a late addition to the presidential traveling party.]

"The Carter proposals," Khalil said after discussing them with Sadat, "were built upon what has been achieved" at the Camp David summit conference last summer. He said they are "very positive and I think the chances for peace are existing at the present time. They are rather good."

Earlier, he told other reporters that Carter's chances for success at bridging the few remaining gaps in the treaty are "75 percent," an assessment that appears to be prevalent here but is hard to reconcile with some descriptions coming from Washington of Carter's trip as a desperate gamble.

Some Egyptian observers believe the United States, Egypt and Israel all are portraying the situation in accordance with domestic and international political considerations, not according to what really is happening.

Khalil said that before Carter arrives Thursday the Egyptian Cabinet plans a special meeting to study the American proposals and see if they satisfy Egypt's negotiating demands. After that, Khalil said, he will relay the Cabinet's decision to Brzezinski.

That gives the impression that the Cabinet here might exercise some independent judgement or overrule Sadat's wishes on some key point. The Egyptian Cabinet is entirely under the thumb of Sadat on important matters of policy and Khalill's remarks were seen as an attempt to demonstrate Egypt's independence of Washington for political purposes.

Khalil has given the impression, supported by other well-placed sources, that Sadat is prepared to accept the Carter proposals without major modifications. Khalil said they did not "deviate much" from Egypt's position on the remaining issues. Another high-level Egyptian source said the Carter visit was "not another Camp David. We're past the stage of serious haggling."

There are, however, still some differences of viewpoint and approach between Egypt and Israel that are likely to remain even if agreement is reached on language that would paper them over. Khalil said today that Egypt is insisting on "the creation of self-government with full autonomy on the Jordan West Bank and the Gaza Strip."

Whatever the language finally adopted in the treaty, the Egyptian and Israeli definitions of Palestinian autonomy are almost irreconcilable. There is a widespread view here that more hard negotiating will lie ahead after the treaty is signed.

There were no meetings today between Sadat or Khalil and the American advance prty, headed by Brzezinski and roving Ambassador Alfred Atherton, a spokesman for the American delegation said. But there were extensive contacts over the massive problems of scheduling, logistics and security that the Carter visit entails.