Israeli officials expressed deep concern today over U.S. Assistant Secretary of State Richard W. Murphy's visit to Amman in which he reportedly may meet with nominees to the joint Jordanian-Palestinian delegation for Middle East peace negotiations.

Foreign Minister Yitzhak Shamir called the Murphy trip "an unprecedentedly grave step that will have serious implications for peace in the area." Shamir charged that any meeting between U.S. officials and nominees to the delegation before it holds direct negotiations with Israel would move the United States one step closer to recognizing the Palestine Liberation Organization.

Aides to Prime Minister Shimon Peres also expressed concern that Murphy might begin a peace dialogue without Israeli presence and at which Palestinians not acceptable to Israel might participate.

A Foreign Ministry official said meetings between Murphy and any PLO member or member of the Palestine National Council -- the PLO's parliament-in-exile -- indirectly would bring about a U.S.-PLO dialogue that would violate Washington's 1975 agreement not to recognize the PLO unless the PLO accepts U.N. resolutions that presume the legitimacy of Israel.

Although the State Department has said that no decision has been made about Murphy meeting in Amman with Palestinians named by King Hussein as potential joint delegation members, an Israeli Foreign Ministry official said today that Secretary of State George P. Shultz told Israel's ambassador to Washington, Meir Rosenne, that Murphy would meet with Hussein, Jordanian government officials "and maybe some Palestinians."

Israeli government sources said Shultz promised Peres in a message delivered today by U.S. Ambassador Thomas Pickering that Murphy would not meet with the joint delegation if it is not clear in advance that the meeting would lead to direct talks with Israel. Shultz also reportedly said the United States will not recognize the PLO as a result of any meetings in Amman.

State Department spokesman Charles Redman confirmed Tuesday that these assurances had been given to Israel.

Murphy was reported to have arrived in Amman this afternoon.

The Foreign Ministry official said Israel opposes any meeting between Murphy and any of the seven Palestinians picked by Hussein from names submitted by PLO Chairman Yasser Arafat.

Peres, representing a more flexible viewpoint in the coalition government, already has accepted two nominees, both PLO supporters who live in Israeli-occupied territory, and is inclined to accept at least one more, senior Israeli officials said.

The two Peres has accepted are Hanna Seniora, editor of Al Fajr, a pro-PLO Arabic daily in East Jerusalem, who left yesterday for Amman saying he expected to meet Murphy, and Fayez Abu Rahme, a Gaza Strip lawyer who is expected to be in Amman later this week.

Peres is also understood to be prepared to accept Nabil Shaat, an Arafat representative in Cairo and a member of the Palestine council.

The difference of views between Peres' and Shamir's ministries on the joint delegation list underscored the fragility of the coalition just as the Cabinet was reported headed for a showdown Sunday over the territorial dispute with Egypt over Taba, a strip of disputed land.

Informed government sources said Peres plans to force a vote on sending the dispute to international arbitration in hope that resolving Taba will encourage Egypt not only to normalize relations with Israel, but to actively involve itself in the joint Jordanian-PLO peace process.

Shamir, who wants the dispute resolved by conciliation, said today that Peres will be in violation of the coalition agreement if he asks the Cabinet to send it to arbitration.