The leading Lebanese Christian party and the Palestine Liberation Organization both held press conference today and accused each other of training Germans as terrorists.

Habib was sent by President Reagan to ease the crisis that followed Syria's stationing of surface-to-air missiles in Lebanon's Bekaa Valley in April. While no Israeli attack on the Syrian missiles has taken place since Habib began his shuttles, neither Syria nor Israel has budged from previous positions. Israel has demanded under threat of attack that Syria remove the Soviet-made missiles but Syria has refused.

Syria moved the missiles into Lebanon after Israeli fighter planes shot down two Syrian military helicopters that the Israelis said were being used to attack Lebanese Christian forces.

"I believe that all concerned would like to see tensions reduced, as evidenced from the fact that the immediate danger of military action that existed when the crisis arose almost two months ago has recedee," Habib said in a statement released by the U.S. Embassy here after his departure.

"It has given way to a diplomatic process in which the United States has been able to play a unique role," he said. He called for "continued restraint" on all sides.

Habib's presence in the area has been credited by diplomats here, in Syria and in Jordan with preventing the threatened Israeli raid on the missile sites. Prime Minister Menachem Begin was reported by the Jerusalem Post as having promised the Reagan administration that Israel would not attack the missiles before the election.

Begin was also reported to hve told the Israeli parliament's foreign affairs and security committee that he deliberately overstated the importance of the Syrian missiles to Israel's security to distract attention from preparations for Israel's bombing raid June 6 on Iraq's nuclear plant.

The Palestine Liberation Organization warned today that Israel is likely to mount another raid on Palestinian positions in southern Lebanon as soon as Habib leaves, as they did last month when he returned to Washington for consultations.

Habib's most recent 16-day shuttle took him to Lebanon, Syria, Israel and Saudi Arabia. Last month he spent three weeks shuttling among the Middle East capitals.

Aside from putting a damper on the immediate threat of an Israeli attack on the Syrian missiles, one of the main results of the Habib mission was to reactivate Arab efforts to end the hostilities here that brought Syrian troops into the country.

Representatives of Lebanon, Syria, Saudi Arabia and Kuwait held two days of talks in Jeddah, Saudi Arabia, this week and are to meet again on July 4 in the Lebanese mountain resort of Beiteddin in a effort to end fighting in Lebanon between the Israeli-supported militia of the Lebanese Christian right, and, on the other side, the Palestinian and Moslem leftists.

Syrian troops entered Lebanon in 1976 under an Arab League mandate to end a bloody, two-year civil war. White the Syrians have been keeping a precarious peace here ever since, they have failed to get the religious and political factions together in an effective national government.