Israeli leak of US plan aims to speed up process. MIDEAST PEACE

In an apparent move to create momentum for Mideast peace negotiations, sources in Israel's Foreign Ministry Wednesday released details of the latest United States peace plan. The US proposals, brought here by Assistant Secretary of State Richard Murphy, were discussed Wednesday in meetings with Foreign Minister Shimon Peres and Defense Minister Yitzhak Rabin. Both ministers, who are members of the centrist Labor Party, are backing the plan.

But Prime Minister Yitzhak Shamir, leader of the right-wing Likud bloc, has expressed reservations about some of its aspects. Mr. Shamir, concerned about a backlash from Likud hardliners, has said little but to dismiss the US proposals as ``fragmentary plans.''

Mr. Peres's Foreign Ministry aides released the details, apparently to refute Shamir's claims that the plan only gave rough, preliminary ideas. Peres has been pushing hard over the past year for an international peace conference, but has been stymied by Shamir, who favors only direct Arab-Israeli talks.

Foreign Ministry sources say the US plan envisages that:

Over the next two months, Mr. Murphy and US Secretary of State George Shultz will try to hammer out an agreed statement of principles guiding both interim arrangements and a final settlement, as well as a schedule for the talks.

Talks, with superpower participation, will formally open in Geneva in mid-April. Negotiations are expected to last six months. Geographical subcommittee meetings will bring representatives of Israel together for bilateral discussions with Jordanian, Syrian, and Lebanese officials. These committees will discuss interim arrangements for the Israeli-occupied West Bank and Gaza Strip and also possibly for the Golan Heights. Though Israel formally annexed the Golan in 1982, the US plan reportedly includes the area.

In October, by when negotiations are scheduled to conclude, a Palestinian self-governing council will be elected and other institutions of autonomy will be set up in the occupied territories. The autonomy period should last no longer than three years before the final status of the territories is agreed upon.

In December 1988, talks on the final settlement will begin - regardless of whether negotiations on the interim arrangements have succeeded. The talks on a final settlement will decide such issues as the ultimate sovereignty over the West Bank and Gaza, border demarcation between Israel and its neighbors, and the status of East Jerusalem.

Shamir's reservations about the US plan center on its deviation from the 1978 Camp David agreement between Egypt and Israel. That agreement stipulates an autonomy period of up to five years before beginning talks on a final settlement. Shamir is unhappy about the shorter autonomy period, and wants linkage between successful interim arrangements and the start of talks on a final settlement.