President Carter and Romanian President Nicolae Ceausescu called on Israel yesterday to join in broadened new Middle East peace talks that would include representatives of the Palestinian people.

In a joint declaration issued at the end of Ceansescu's two-day state visit, the two presidents gave their support based on Israeli withdrawal from Arab lands occupied in the 1976 war, insurance of Israel's territory and seceurity and "respect for the legitimate rights of the Palestinian people."

But as the wording of the declare-tion indicated. Carter refused to go along with Ceausescu's separate contention that the Palestiniars should be represented in future talks by the Palestine Liberation Organization. Israel refuses to negotiate with the PLO.

Ceausescu who has special ties with both sides in the Middle East dispute, reportedly had told Carter the PLO is movin toward recognition of Israel's right to exist and had urged the American president to ease U.S. opposition to dealing with the PLO.

However, U.S. sources were quick to point out. Carter refused: and the joint declaration's language did not go beyond past U.S. formulations about some form of representation for the Palestinians in peace talks.

A similar patching over of differences also was evident in the declaration's language on human rights questions. Ceausecu's tight control of Romania's internal life is considered highly authoritarian even by the standards of Eastern EUrope's communist societies - a fact that provoked ROmanian exiles and right activistsdemonstrations outside the WHite House yesterday.

In dealing with the this question, the declaration called fpr U.S. Romannian relations to include "observance of and promotion of respect for human rights and fundamental freedoms.including all the conditions required for a free, dignified and prosperous life."

But, it also added language insisted on by the ROmanians, acknowledging "the right of each state freely to choose and develop its politicial social, economic and cultural system.'

In an appearance at the National Press Club, Ceausescu sounded this same note repeatedly. Romania, he made clear, will not tolerate interfence in its internal affairs, even if questions about the rights situation there stir opposition to the Ceausecu regime retaining its coveted most-favored-nation tariff status with the United States.

In response to questions, he said again and again that human rights, including the right to emigrate. are fully respected in his country.He also denied that there is any discrimination against ROmania's Hungarian, German and Jewish minorities.