For the second time in little more than a month, the name of Palestinian terrorist Abu Nidal has been linked to a new wave of horrors emerging from the Middle East.

First, the Egyptians accused Abu Nidal of working with Libyan leader Muammar Qaddafi to stage the hijacking of an Egyptair Boeing 737 to Malta on Nov. 23. Now an anonymous phone caller in Spain has claimed responsibility for yesterday's airport attacks in Vienna and Rome in Abu Nidal's name.

The carnage in both capitals is "consistent with the Abu Nidal group," a western diplomat here suggested this morning.

Although there has been no solid confirmation of Abu Nidal's involvement with any of these incidents, he has emerged suddenly from the depths of internecine Arab intrigues and assassinations onto the world stage as the most infamous terrorist since the notorious "Carlos" of the late 1960s and early 1970s.

But his reputation has been building, fed by legend and sometimes inflated by one Arab politician or another for reasons of political convenience, for a long time.

He is at once an implacable foe of Israel and in many ways the deadliest enemy of the Palestine Liberation Organization. He has been accused of killing Jewish schoolchildren in Antwerp in 1980 and has claimed responsibility for the attempted assassination of Israel's ambassador to London in 1982. But Abu Nidal is best known in the region for murdering Arabs, especially Palestinians, who he believes might seek peace with Israel.

At the top of Abu Nidal's proclaimed death list is his one-time ally and leader, PLO Chairman Yasser Arafat. The PLO, in turn, has vowed repeatedly to eliminate Abu Nidal whenever and wherever it can catch him.

Abu Nidal's myth has been assisted by his mystery. In his entire career, he is believed to have granted only three interviews. One, early this year, was meant mainly to establish that reports of his death were false. The second, given to the West German news magazine Der Spiegel in Libya this fall, appears to be his most revealing.

But the aura of treachery and intrigue that surround the man is such that diplomats and intelligence sources question virtually every word attributed to him.

Abu Nidal's real name is Sabri Khalil Banna. He told Der Spiegel in its Oct. 14, 1985, issue that he was born in 1937 to Syrian parents living in what was then Palestine.

"My father was very rich," said Abu Nidal. "He married 13 women. I am the son of the eighth wife and have another 16 brothers and eight sisters."

Expelled from a French mission school in Jaffa, he then attended an Islamic school in Jerusalem until the outbreak of war in the late 1940s, when his family left Palestine and was scattered throughout the world. For a while, Abu Nidal told Der Spiegel, he worked for the oil company Aramco in Saudi Arabia but was arrested, tortured and deported. He has, he said, one wife and three children.

In the 1960s Abu Nidal was one of the early advocates of "armed struggle" against Israel and eventually became a member of Arafat's Fatah organization. But after the PLO was expelled from Jordan in 1970 he began to have violent differences with Arafat, and the break was made complete in 1974 as Arafat began his own long struggle to shed the label of "terrorist."

As Abu Nidal portrayed himself to Der Spiegel, he is the standard-bearer of implacable resistance to what he calls "the Zionist entity."

"The man who introduced the word Israel into the Arab language was this traitor Arafat," Abu Nidal said.

Any means, including bombs and political assassinations, are "very legitimate indeed" in the fight against Israel, he asserted. "It's not even the biggest crime that the Zionists have occupied my Arab home. It would be a bigger crime if we would tolerate these Zionists leaving our home alive."

But Arafat and his lieutenants, who cling tenaciously to their independence from the dictates of other Arab leaders, dismiss Abu Nidal now as the servant of Arab governments intent on using Palestinians for their own ends.

The current PLO leadership suggests that Abu Nidal's main goal is to discredit them and to hamper their efforts to gain respectability, credibility and a central role in the peace process with Israel.

On several occasions in the past, Arafat's people have gone so far as to suggest that Abu Nidal is in fact working for right-wing Israeli factions, so successful has he been in providing Jerusalem with pretexts, in this view, to attack the mainstream leadership of the PLO.

The most conspicuous case was Abu Nidal's attempted assassination of Israeli Ambassador Shlomo Argov in London in 1982, followed days later by Israel's invasion of Lebanon aimed at destroying Arafat's PLO.

In a lengthy interview with The Washington Post earlier this month, however, Arafat's second in command of military operations and one of Fatah's most enduring stalwarts, Khalil Wazir, adopted the less convoluted line that "Abu Nidal is one who is a tool in the intelligence services of the Arabs."

"Once he was in the hands of the Iraqis, now he is in the hands of the Syrians and Libyans," said Wazir. "He is in good health. He is in Tripoli Libya . . . . His group in Syria is working with the Syrians, in Libya with the Libyans."

Both Libya and Syria are violently opposed to Arafat as well as to Israel.

Wazir said that Abu Nidal, to recruit his force of gunmen, combs North Africa and Europe for Palestinians and other Arabs, "searching for workers who need money."

In both the Egyptair incident and, according to initial reports, in yesterday's attacks, some of the terrorists were traveling on Moroccan passports.

In the Der Spiegel interview, Abu Nidal insisted that he and his people "are not mercenaries."

In the long history of his operations, both acknowledged and alleged, Austria has been a favorite site for his plots. At one point Abu Nidal reportedly planned to assassinate former chancellor Bruno Kreisky, who had supported efforts toward PLO-Israeli dialogue. His men are alleged to have attacked a Vienna synagogue in 1981 and, the same year, two of his agents were reported arrested at the Vienna airport after arms and explosives were found in their luggage.

Italy, although it has not been the focus of Abu Nidal's fury in the past, may have become a target now because of the present government's determined efforts to work with Arafat toward a Middle East peace settlement.

As western intelligence agencies, Israel and moderate Arab leaders begin the work of sorting out responsibility for yesterday's atrocities, it is Abu Nidal's connections to governments, not underground operations, that are likely to be given the most weight.

Although for a period in the early 1980s Abu Nidal seemed able to operate out of Iraq and Syria at the same time despite the bitter enmities between the two countries, he now appears firmly a part of the radical axis of Syria, Libya and Iran.

In Der Spiegel, Abu Nidal was quoted as a loyal disciple of the Baath Party and the doctrine of "greater Syria" associated with Syrian President Hafez Assad. Of Libya's Qaddafi, Abu Nidal said, "We have a deep and strong friendship . . . . He is a big help for us."