The start of Israeli troop pullbacks from West Beirut and U.S. special envoy Philip C. Habib's return to the area have prompted an effort by Egypt to encourage the United States to press ahead with its Middle East peace plan.

A ranking Egyptian official said today that President Hosni Mubarak's remarks in a speech yesterday urging other parties to seize the opportunity made available by President Reagan for a fresh start reflected Egypt's eagerness for an early resumption of the talks stalled for two years. Mubarak urged that the opportunity be used to "turn negative aspects of the plan to positive ones on the negotiating table."

The progress in Lebanon in the past two days has prompted optimism that the United States is working on easing tension there in preparation for focusing on broadening the Camp David peace process to involve Jordan and Palestinians, the Egyptian official said.

The official reaffirmed that Egypt has made the resumption of the talks on Palestinian autonomy conditional on Israeli withdrawal from Beirut. He indicated that when Israel completes its pullout from the Lebanese capital and shows signs of readiness to withdraw from the rest of Lebanon, Egypt also would be willing to send its ambassador back to Tel Aviv. Cairo recalled the envoy Monday.

The timing of Egypt's return to negotiations also depends on the outcome of coordination efforts between Jordan and the Palestine Liberation Organization. Meanwhile, Egypt is seeking to strengthen its position in the peace process by building on its reestablished ties with the PLO.

Egypt has welcomed Reagan's invitation to Jordan to join in the peace talks as it does not want to be the only Arab party negotiating with Israel and exposing itself to criticism from Arab states that disagree with the Camp David formula.

Egyptian officials said Egypt would not oppose the formation of a joint Jordanian-Palestinian delegation to the talks as part of the coordination efforts that have already started. But they said Egypt will insist on PLO representation in the team and approval of its makeup.

Egypt and the PLO have said they support several points in the plan announced by Reagan three weeks ago but they regard the proposed link of an autonomous Palestinian entity to Jordan as the main negative aspect.