Israel is going to offer Egypt sovereignty over all of the Sinai Peninsula, provided the Israelis can remain in the settlements they have established in northern Sinai and special arrangements can be made for stategic points elsewhere, authoritative sources here said today.

Israel is prepared to be flexible about how the strategic points locations in the Sinai are controlled, the sources said, as preparations continued for Prime Minister Menahem Begin's trip to Egypt on Sunday to present his proposals to President Anwar Sadat.

In addition to a detailed plan for the Sinai, Begin is said to be planning to submit to Sadat a more general proposal for autonomy on the West Bank and the Gaza Strip.

In the Sinai, Israielis say they would return such points as Sharm el-Sheikh at the entrance of the Gulf of Aqaba and the mountain passes astride the tank routes through Sinai to Egypt if there is an Israeli, U.S. or U.N. presence, or some combination of the three in those places.

So long as the monitors in those key points cannot be ordered out by Egypt, the Israelis indicate that they are not overly concerned about how their formal, legal status is described.

Armed with maps, Begin is understood to be prepared to tell Sadat that the Israelis want to maintain such northern agricultural settlements as Yamit, near Rafiah, south of the Gaza Strip.

The Israelis are said to be seeking long-term leases on such settlements as Yamit, which is practically a small town. Reports from Egypt say Sadat would only be willing for Israelis to stay if they took up Egyptian citizenship, something Israel is unlikely to accept.

Energy minister Yitzhak Mofai said today that he hoped Israel would be able to continue to pump oil from the Sinai. He said that although the Sinai's petroleum resources are enough to meet all of Israel's needs, he did not think this should prove to be an obstacle to peace. The implication seemed to be that Israel would not refuse a deal with Egypt if the Egyptians do not let the Israelis continue to take the oil for themselves.

Egypt is poor in energy resources, and has encouraged a number of multinational companies to search for oil off its Mediterranean coast. For Egypt, the oil of the Sinai would be a major boost to an economy beset with major problems, including having to spend precious hard currency or tun to its oil-rich Arab friends for special deals for oil.

Referring to the autonomy issue for Gaza and the West bank, Israeli state radio reported that Begin will propose the creation of three cantons: Gaza, with its 400,000 inhabitants, and Judea and Samaria on the West Bank. The 700,000 Palestinian Arabs on the West Bank are roughly divided between the two provinces of Judea and Samaria.

There was no immediate confirmation of the radio report, but officials said it sounded logical. By dividing the West Bank in half and creating two regional assemblies and central administrations, Israel could hope to forestall creation of a united entity that could eventually become an independent Palestinian state.

As for the Israelis settlements on the West Bank, authoritative sources say, the problem is not the same as in the Sinai since they are not on soil that will come under foreign soverneignty in any peace settlement.

The Israelis say they have not come to the point of considering what kind of authority the local administration in Judea and Samaria would exercise over the numerous Israeli settlements, most of which are concentrated in the Jordan Valley.

Begin will not offer any proposals on the return of the occupied Golan Heights to Syria, the sources said. The said that since Syria has expressed no interest in the Sadat-inspired peace talks, there is no point for Israel to make any concrete offers.

Even though no recognized Palestinian representatives have expressed interest in the talks either, the Israelis say thay are willing to discuss the Palestinian issue in detail because Sadat says he wants a solution for the Palestinians.

The implication is that Sadat has not been pressing the Israelis to come up with anything of Syria. He has, however, been telling the Israelis that they should deal with Yasser Arafat, the leader of the Palestine Liberation Organization, because he is a moderate, the sources say.

The Israelis stress that they will not sit down at any conference table anywhere with the PLO, which they condiser a terrorist organization.

The Israelis are also expected to come up with suggestions for Jerusalem. Many formulas have been put forward over the years, including a plan by associates of Jerusalem Mayor Teddy Kollek to establish a self-ruling Arab and Jewish boroughs under an overall city government. Alongside this idea is one of creating a sort of Arab Vatican City on the Temple Mount, the site of the principal Moslem holy places.

One Israeli source, recalling his government's insistence that Jerusalem is "negotiable," added, "negotiable and returnable are not synonymous."

Meanwhile, Begin spent nearly four hours today persuading his own Likud parliamentary bloc to back hos plans. They have been particularly upset by the reports of the government's autonomy offers for the West Bank. All but three of the 43 Likud deputies in the 120-member Parliament finally voted to back Begin. Two voted against him and one abstained.

Deputy Premier Yigael Yadin got the unanimous backing of his 15 Democratic Movement for Change deputies, who form the left wing of the governing coalition. The coalition's other main component, the 12-member National Religious Party, reportedly voted in yesterday's Cabinet meeting against inclusion of anyone besides Foreign Minister Moshe Dayan and Defense Minister Ezer Weizman in Begin's delegation to the talks in Ismailia Sunday as long as one of its ministers was not on the delegation.