U.S. special Ambassador Sol Linowitz completed his final mission to the Middle East today, declaring that Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin agree that "important progress" has been made in the West Bank-Gaza Strip autonomy negotiations and that a comprehensive peace can be reached without deviating from the Camp David process.

Linowitz told a news conference there are no insoluble problems facing the autonomy negotiators, and he is confident his successors under the Reagan administration can find a common ground in the Camp David formula on which to preserve Israel's security and provide a solution to the Palestinian problems.

Linowitz met with Sadat in Cairo before coming here on a mission that aides said had a twofold purposes: to agree on a summary of progress made to date so that there will be no misunderstandings when the stalled autonomy talks resume, and to pinpoint both sides' positions on unresolved issues so that he can brief the president-elect and recommend the next step in the talks.

Throughout his three-day visit here, Linowitz went out of his way to assure the Israelis that Ronald Reagan -- contrary to a widely held belief here -- does not favor the so-called "Jordanian option" to the Camp David process. Today he noted that the process already includes a role for Jordan in determining the final status of the West Bank after a five-year transition period of autonomy.

Linowitz critized the independent peace initiative launched by the European Common Market nations, which have called for the Palestine Liberation Organization to be involved in the talks. He is due to stop in London on his way to Washington to attempt to discourage Britain from Participating in the initiative.