Israeli Foreign Minister Yigal Allon yesterday criticized informal contacts said to have taken place between Israeli personalities and representatives of the Palestine Liberation Organization.

He told students at Haifa that such contacts extended the lifespan of the PLO as a political factor by creating the impression that the organization could serve as a partner for future talks with Israel.

"This has no chance and no hope," Allon said. "Not only can they not be considered representatives, they are not even worth boycotting."

The PLO denied in Paris and Beirut Israeli reports that its representatives had met the leaders of an Israeli peace group in Paris on Saturday and signed a joint statement implying PLO acceptance of the existence of Israel.

Retired Maj. Gen. Matityahu Peled, chairman of the Israel Council for Israeli-Palestinian Peace, today insisted that the contact had taken place.

The Israeli ambassador in Paris, Mordecha Gazit, also confirmed the meeting, but said he regretted it.

The PLO office in Paris said that "no Palestinian leader mandated by the PLO has signed" any document such as the one described by Peled.

A senior PLO envoy said in Bahrain, however, that the organization might agree to take part in a reconvened Geneva conference on the Middle East as part of a unified Arab delegation.

Mahmoud Abbas told reporters that the PLO would do so if it received a direct invitation from the conference's co-chairmen, the United States and Soviet Union.

In Jerusalem, Prime Minister Yitzhak Rabin told members of a leftist factions of his Labor Party that Israel is prepared to make territorial compromises along all its present defense lines in return for guarantees of peace from Arab countries.

In Cairo, Egyptian Foreign Minister Ishmail Fahmi held separate talks with the U.S. and Soviet ambassadors on moves to reconvene the Geneva conference.

In Beirut, meanwhile, at least 17 persons were killed in a powerful explosion at the gate of a Christian militia garrison. Reuter quoted Phalangist Party sources as saying 24 persons were killed in the blast, but AP said the party radio reported 17 dead. Both news agencies said more than 50 were injured.

The bombing was the worst single incident of violence in Beirut since a predominantly Syrian peacekeeping force ended in civil war in most of Lebanon in November.

Lebanese security officials said a preliminary government report has put the total casualty toll in the 19-month civil war at 63,875 persons killed, 217,593 wounded and about 7,800 missing.

Censorship officially went into effect in Beirut with the publication of rules and procedures in the city's newspapers. The Interior Ministry set up two press censorship centers.

Baghdad Radio announced that Iraq had opened a pipeline enabling it to bypass Syria and ship its oil to the Turkish Mediterranean coast. The broadcast said the 6,250-mile pipeline will carry crude oil from the Kirkuk fields in northern Iraq to Dortylo, Turkey.