A proposed new U.S. Mideast peace plan calls for Israel and Jordan, working through a shuttling U.S. mediator, to agree by September on limited Palestinian self-rule in the West Bank and Gaza Strip, with direct negotiations on the final status of the territories to follow in December, U.S. officials and other sources familiar with the plan said yesterday.

The specifics of the U.S. plan have been the subject of intense speculation this week. Secretary of State George P. Shultz, reacting to the unrest that has gripped the West Bank and Gaza since December, had begun contacts last week with Israeli and Arab leaders on a new initiative to get the long-stalled Middle East peace process moving again.

The sources stressed that the plan is still in a highly exploratory, evolving state and that no predictions can be made at this point about its chances for success.

But some sources said that one of the major initial obstacles had been cleared with a notification by Jordan's King Hussein, who thus far has resisted all efforts to entice him into peace talks with Israel, that he is interested in the plan. The sources said that Hussein told Philip C. Habib, a special envoy Shultz sent to Amman last weekend, that while he is not yet ready to make a clear commitment, he regards the plan as having promising aspects that should be explored further.

Essentially, the sources said, the initiative is based on the moribund 1978 Camp David plan for creating an interim period of Palestinian autonomy in the occupied territories.

But, the sources added, the new initiative greatly accelerates the Camp David timetable of a five-year, interim autonomy period before the start of negotiations on a final settlement. Instead, the aim now is to achieve that goal by the end of the year.

The sources said the quickened pace is intended as an inducement to Hussein, who refused to accept the Camp David agreement on the grounds that Israel could manipulate the autonomy period to retain control over the territories almost indefinitely.

The new timetable was made possible by what the sources called "a major concession" by Israeli Prime Minister Yitzhak Shamir that was communicated to Shultz last week. According to the sources, Shamir said that despite anticipated heavy opposition from members of his Likud bloc who believe that the West Bank and Gaza should be absorbed into Israel, he now is willing to shorten drastically the interim period before moving to negotiations on whether the territories stay with Israel or are transferred to Jordanian control.

The sources said that the idea of having the initial talks on creating an autonomy plan be conducted indirectly by an American mediator is intended to protect Hussein from becoming isolated in the Arab world and subject to charges that he is betraying the Palestinian cause. Negotiations on direct talks between Jordan and Israel foundered last year because Hussein's insistence on conducting them under the protective umbrella of an international conference was rejected by Shamir.

According to the sources, Hussein, in his weekend talks with Habib, made clear that he still wants such an arrangement as the framework for direct talks and will

insist on a clear-cut understanding with Israel on that issue before he commits himself to the U.S. proposals.

The sources said that in the ear- ly exploratory stages, the Amer- ican shuttle mediating probably would be done by Habib or Richard W. Murphy, assistant secretary of state for Mideast affairs. If the

effort shows promise of success,

the sources continued, Shultz is likely to take a still unspecified hand in the process or assign the task to a new, high-level special envoy.

The main task, in that first phase, would be to achieve a plan that would give the Palestinian inhabitants of the West Bank and Gaza limited self-rule through an elected authority that would take over many of the functions now performed by the occupying Israeli army. The elected officials also would represent the Palestinians in

the negotiations on a final settlement.

The sources said Israel has made clear that it will not accept creation of an independent Palestinian state nor permit the Palestine Liberation Organization (PLO) to be represented in the direct talks. However, the sources said, as a practical

matter, the Israelis are aware

that the great majority of West Bank and Gaza residents are PLO sympathizers and Israel thus will have to use what one source called "some studied ambiguity" if any Palestinians are to be wooed into cooperating.

That source said the expectation is that Israel will insist that to be eligible to hold office, Palestinians must be residents of the territories rather than exiles who have spent the 20 years of Israeli occupation elsewhere. It also will veto Palestinians known to be agents of the PLO, but in other respects, the source said, Israel probably will

follow a policy of not looking too closely at the backgrounds of

those Palestinians willing to get involved.

In testimony before the House Foreign Affairs Committee yesterday, Shultz acknowledged that the administration is seeking ways to improve the short-run political aspirations of the Palestinians and find a basis for a long-range solution, but he refused to discuss specifics. White House spokesman Marlin Fitzwater also said active explorations are under way, but he denied that the administration has put forward detailed new proposals.