The State Department announced yesterday that, after Secretary of State George P. Shultz visits Israel May 10, he will travel to Cairo and Amman for talks with Egyptian President Hosni Mubarak and Jordan's King Hussein.

Announcing Shultz's change in plans, State Department spokesman Bernard Kalb cautioned against interpreting it as a sign of "some dramatic breakthrough" in the current mission of Assistant Secretary of State Richard W. Murphy.

Murphy has been in the Middle East for two weeks exploring "practical steps" that might lead to renewal of the long-stalled Mideast peace process.

Kalb also maintained that Murphy's mission has suffered "no setback" and said Murphy had held "a series of informative and useful meetings" with Arab and Israeli leaders.

"We expect this to be a slow, gradually developing process, and I would advise against expectations of sudden breakthroughs or dramatic events," Kalb said.

Shultz is taking along no new U.S. proposals on ways to break the deadlock in the long-stalled peace process and is likely to confine himself mostly to appealing for more Arab support for Jordan and Egypt in their efforts toward resumption of Arab-Israeli negotiations, according to one U.S. official.

The change in Shultz's plans to include the two Arab capitals, according to one U.S. official, was dictated mostly by administration concern that a measure of balanced U.S. interest be shown between Israel and the Arab world during his trip. The initial purpose of his visit was to participate in a Holocaust memorial ceremony in Israel.

An indication that Murphy has apparently encountered difficulty on his mission came yesterday in Israel, where he briefed Prime Minister Shimon Peres and Foreign Minister Yitzhak Shamir on his talks with Arab leaders.

An Israeli official said Murphy told Peres and Shamir that he has not found an acceptable formula for including Palestinians in a Jordanian-proposed joint delegation that would eventually negotiate with Israel, according to news agency reports from Jerusalem.

Kalb refused to say whether Murphy is making progress. But other State Department sources acknowledged that the going has been slow and no agreement reached on the makeup of a Jordanian-Palestinian delegation. One source said, however, that the process is taking "small steps" in the right direction.

These officials also discounted the possibility that Murphy might meet with such a delegation before his scheduled return here next week.