At least 82 persons were killed and 211 wounded in yesterday's artillery battle, Beirut radio reported today, as the latest cease-fire began to take hold and negotiations for a political settlement resumed.

The radio reports said there has been an increase in fighting in the countryside between Israeli and Syrian forces as well as among the various rival political and military factions vying for power in Lebanon.

Israeli radio and the Phalangist Voice of Lebanon both broadcast reports of Israeli-Syrian clashes in the southern Bekaa Valley around Lake Qirawn. Six Yemeni guerrillas, who the Israelis said had come from Syria, were reportedly killed, and the Israelis announced that three of their soldiers were wounded.

While the number of Palestine Liberation Organization casualties in yesterday's fighting in Beirut remained unknown, Israeli Army spokesman Col. Paul Kedar confirmed earlier reports that three Israeli soldiers were killed and 28 wounded.

The latest cease-fire, the sixth since Israel's June 6 invasion of Lebanon, took hold at about 9:30 p.m. after frenetic efforts by U.S. special envoy Philip C. Habib to halt a day of intense tank, artillery and rocket fire in and around Beirut. Relief workers took advantage of the respite today to dig victims out of the rubble of houses and apartment blocks in the Palestinian camps and neighborhoods of southern Beirut, the scene of the heaviest bombardment.

One Beirut newspaper said yesterday was the single most destructive day and night in the capital of the past seven years, including the 1975-76 civil war.

Hundreds of buildings were wrecked or burned in predominantly Moslem West Beirut and its southern suburbs on the one side and mainly Christian East Beirut and the Israeli-occupied hills to the east and south on the other. In some places shells were landing at a rate of 30 a minute, and one estimate said a total of between 8,000 and 10,000 may have been fired.

A dozen shells landed on the French ambassador's residence, apparently fired from the Israeli side, and 55, evidently shot by the Palestinians, were reported to have hit the presidential palace at Baabda, which is surrounded by Israeli military installations. President Elias Sarkis was reported to have taken refuge in a bomb shelter.

There was a slight redeployment of exposed Israeli troops and gun positions around the presidential residence to provide better protection for the Israeli forces, Washington Post correspondent Leon Dash reported.

Today, President Sarkis, Habib and Lebanese Prime Minister Shafiq Wazzan were obliged to hold talks in a basement while repair work was going on in the hilltop presidential residence's ground floor offices and second floor living quarters. No progress in the talks was reported.

According to former prime minister Saeb Salam, a key figure in the negotiations, there has been no change in Habib's demand that an international peace-keeping force not be deployed in Beirut until after trapped Palestinian guerrillas withdraw from the capital on their way out of Lebanon.

The PLO is demanding that the international force, together with Lebanese Army units, come in to supervise disengagement of the combatants before any such pullout, which the PLO insists must be negotiated with the Lebanese government free of any Israeli pressure on the capital.

In Athens, the Greek government announced it would be willing to send 300 men to participate in a peace-keeping force if the United States, the Soviet Union and all parties to the conflict agreed, special correspondent Andriana Ierodiaconou reported. Until now, Moscow has opposed the participation of U.S. troops in a peace-keeping force to supervise the Palestinian withdrawal.

Greece has also offered to lend its Navy to carry Palestinian guerrillas out of Beirut.

A difficulty facing the negotiators is the announcement by Syria Friday that it would refuse to accept an estimated 5,000 to 6,000 Palestinian fighters evacuated from Beirut as part of the political settlement sought by Habib.

According to Salam, the next step in the talks is either "a change in the American position or a change in the Syrian position."

According to a senior PLO official, "very little has been agreed upon," with the PLO insisting on discussing disengagement first.

He said the PLO wanted any international force entering Beirut to be under U.N. auspices, but that its composition was up to the Lebanese government.

"There is no objection in principle to American participation," he said.

According to this official, the Soviet Union has told PLO leaders that it is putting "maximum pressure" on Washington to prevent the Israelis from assaulting Beirut. "They're saying to the Americans, 'We will not permit it,' " the official said.

He added that when pressed about what their response would be if the Israelis went ahead with an assault anyway, Soviet officials here have told the PLO that Moscow would take action, but have declined to elaborate.

The Israeli Army spokesman Col. Kedar said that Red Cross food convoys headed for West Beirut would no longer be turned back at Israeli-controlled checkpoints.

News services reported the following developments:

West German Foreign Minister Hans-Dietrich Genscher, visiting Amman, Jordan, appealed to all parties in the Lebanon conflict to "end all actions which sharpen . . . rather than solve the conflict." The West German official was scheduled to confer with government officials in Jordan and Egypt.

Saudi Arabia and its five allies in the Gulf Cooperation Council resumed ministerial talks in the kingdom in an apparent bid to work out a joint stand on the Israeli siege of Beirut.

The official Saudi news agency said the council, which also includes Kuwait, Bahrain, the United Arab Emirates, Qatar and Oman, was debating the latest developments in the Arab world. This was taken to mean that the talks, a regular meeting held every three months, centered on Israel's invasion of Lebanon and the Persian Gulf war betwen Iran and Iraq.