A spokesman of the Palestine National Council, the Palestinians' parliament-in-exile, today described President Carter's meeting a Palestine Liberation Organization representative at the United Nations in New York as "a positive sign."

The spokesman, Mahmoud Abbadi, said in answer to a question: "This is a positive sign and a good reference from President Carter toward recognizing the national legitimate rights of the Palestine people.

"We hope for more such right attitudes toward the legitimate rights of the Palestinians."

Carter met the PLO representative Thursday night in a receiving line in the UN delegates' lounge at a reception give by Secretary General Kurt Waldheim.

Carter told reporters afterward that "I just shook hands" with the PLo officials, Hasan Abdel Rahman.

The President said that there would be no further contack between the United States and the PLO "until the PLO changes its attitude toward Israel."

Israeli representatives, meanwhile, were openly upset by the Carter-PLO meeting. Israeli Ambassadoir Chaim Herzog said that he resented the presence of the PLO at the reception in view of the organization's reaffirmation just this week of "its commitment to destroy Israel."

The PLO "does not belong in any civilized gathering, let alone one to honor the President of the United States," Herzog said.

The original plan for Carter's visit to the United Nations envisaged invitations limited to countries holding full membership. Later the White House called the United Nations and said it would not object to Waldheim's extending invitations to observer delegations which include the PLO. To reduce the political impact of a meeting between the President and the PLO, according to U.N. officials, the White House asked the United Nations to cancel television coverage of the reception and to cancel plans for receiving line.

When the guests emerged from the General Assembly chamber and entered the reception room, the President decided that in the interest of dignity and order a receiving line should be formed, according to U.N. officials.