King Hussein is reportedly prepared to grant amnesty to the Palestinians who once tried to topple his throne if that will help bring about a peaceful evacuation of the Palestine Liberation Organization guerrillas under siege by the Israeli Army in Beirut, according to palace and government officials here.

In discussions in the capital today, officials said amnesty could be offered to any of the several thousand Palestinian guerrillas in Beirut who hold Jordanian passports or residency papers and who have been on the rolls of the security forces since September 1970. The king expelled the PLO guerrillas from Amman at that time after they sought to take control of the city much as they have done since in West Beirut.

Hussein, who will celebrate his 30th anniversary on the throne next week, promised to take in 1,800 to 2,500 Palestinians when he met with U.S. special envoy Philip C. Habib in London 11 days ago, according to palace sources.

"The king told Mr. Habib that Jordan would take in all Palestinians with Jordanian passports just like it would take in any other Jordanian citizen," said Minister of Information Adnan Abu Odeh, a close confidant of the king.

The one condition for their entry, however, Odeh said, was that they come to Jordan "without guns," as other Jordanians are required to do.

This condition clearly reflects the Jordanian government's bitter memories of 1970 when the PLO had its headquarters in Amman and gradually sought to become a state within a state. The September showdown that resulted between the king's Bedouin Arab Legion and the guerrillas is still recalled as "Black September" by the PLO.

Odeh said that many of the PLO fighters who had criminal cases pending because of their actions before their expulsion had been given a royal reprieve in 1976.

As for the rest, whose numbers he could not specify, the minister said he did not think they would be subjected to judicial proceedings if they returned because "their suffering in Beirut has been punishment enough."

Palace sources who did not want to be identified said that it was expected that a full amnesty could be enacted when and if Jordanian Palestinians left Beirut along with the other PLO forces.

The message about a possible amnesty also was passed on two weeks ago to a U.S. congressional fact-finding delegation headed by Rep. Robert McCloskey (R-Calif.) after a meeting here with Crown Prince Hassan and other officials.

Western diplomats saw the king's agreement to take in some of the trapped Palestinians as both a gesture of support for the Habib mission and as a move to appease his kingdom's large Palestinian population. Palestinians here have been seething over the spectacle of their brethren being bombed and shelled by the Israelis in West Beirut.

More than half of Jordan's 3.1 million population is of Palestinian origin, many of them refugees from the West Bank, which was part of Hussein's Hashemite kingdom until its occupation by Israel in 1967.

Although Hussein's control of his kingdom is not questioned, a Western diplomat termed the mood among Palestinians and Jordanians alike as a "smoldering volcano" whose eruption from frustration could have unforeseen consequences.

The government's unease was made evident yesterday when a group of about 100 well-dressed women of Amman sought to converge on the U.S. Embassy to present a petition protesting the Israeli siege of Beirut and what they termed U.S. responsibility for not stopping it.

Jordan allows no public demonstrations not previously approved by the government and the petition presentation was aborted with a massive show of police power. The avenue in front of the U.S. mission was sealed off by police cars, and about 50 policemen, armed with baseball bat-sized wooden batons, cleared the sidewalks before the demonstrators could reach the embassy gates.

Jordanian officials maintain that their government is fully behind Habib's efforts. But like Egyptian President Hosni Mubarak, Hussein privately has urged Habib to link any agreement over Beirut with a more comprehensive agreement that will guarantee real progress toward self-determination for the Palestinians, sources here said.