A Palestinian newspaper reported today that Abu Nidal, a Palestinian radical whose small terrorist organization was blamed for killing or wounding more than 900 people in 20 countries, had been found dead in his home in Baghdad. He had several bullet wounds and was believed to have killed himself, the paper said.

Neither Israeli nor American intelligence officials could confirm the report in the paper, Al Ayyam, but they said that if the account of the wounds was true, his death was probably not a suicide.

The Palestinian official charged with relations with Iraq, Azzad al-Ahmad, said he was checking the report with Baghdad. But senior Palestinian officials said privately that it appeared to be true.

Abu Nidal's brother, Muhammad al-Banna, reached by Reuters in the West Bank, said he had not talked to him for more than 40 years and had heard about the death only from news reports.

Al Ayyam, which is published in Ramallah, said Abu Nidal appeared to have died three days earlier, citing ''informed sources.'' The newspaper gave his age as 65.

He is believed to have lived in Baghdad since 1998, and American intelligence officials said he was believed to have been suffering from heart disease and diabetes and was a heavy drinker.

The officials said that his network had become largely moribund and that there was no evidence that he had conducted any terrorist actions since his move to Baghdad.

Born Sabry al-Banna to a prosperous Palestinian family from Jaffa, now an Israeli port town, Abu Nidal -- the name means father of the struggle -- broke with Yasir Arafat's Fatah movement in the early 1970's and became a sworn enemy of the Palestinian leader, whom he reportedly tried to assassinate in 1974.

He formed his own group, Fatah Revolutionary Council, with Iraqi support, and rapidly established it as one of the most murderous terror organizations.

Among his most notorious crimes was an attack with guns and grenades on the check-in desks of Israeli and American airlines in Rome and Vienna in December 1985, in which 19 people were killed and more than 100 were wounded. Another attack, in which the Israeli ambassador to London, Shlomo Argov, was critically wounded, was the trigger for Israel's invasion of Lebanon in 1982.

Though his primary targets were Israel and Jews, his group also focused its hatred on Arabs and Arab countries that moved toward moderation in their stance toward Israel, and on the United States, Britain and France.

Yossi Melman, an Israeli journalist who wrote a book about him, said he came to be ''a sort of gun for hire,'' who did jobs for Iraq against Syria, and for Syria against Jordan.

David Kimche, a former Israeli intelligence and Foreign Ministry official, told Israel Radio that Abu Nidal ''was completely on his own.''

''He had a very small group of fanatics who worked with him, and they were very active, but he was never part of the group with Habash, Hawatmeh and all the rest,'' Mr. Kimche said, referring leaders of other radical Palestinian groups. ''They all regarded him as a bit of an oddity, both because of the way he behaved and because of the way he regarded the rest of the Palestinian movements.''

Israeli officials said that if the report of Abu Nidal's death was true, he had most likely been assassinated by Palestinians, especially since the first report of his death came from a Palestinian paper. They noted that there was no shortage of people who wanted him dead, including Mr. Arafat, who reportedly tried to assassinate him at one point.

But the officials also noted that this was not the first time that Abu Nidal had been reported dead. Mr. Kimche said he had been reported dead at least three or four times, ''so it's hard for me to know if he has really died now, or if he died several years ago.''

''He was one of the bitterest and most contemptible of our enemies,'' Mr. Kimche said.

According to Mr. Melman, Abu Nidal's family was driven from Jaffa at the creation of Israel in 1948 and became refugees in Nablus. Abu Nidal moved to Saudi Arabia, where he worked as a technician and an electrician, and where he joined Al Fatah.

After forming his own group, he had his bases first in Iraq, then in Syria, then in Libya. Though never numbering more than a few hundred, the group was well financed and deadly.

The list of terror acts attributed to him begins in 1973 with an attack on a Pan Am jetliner in Rome, in which 32 people were killed. The next year, a TWA jet flying from Israel to Greece was blown up over the sea, killing 88. In the next 20 years, the list stretched to include attacks on more jetliners, a cruise ship and airports in Rome and Vienna.

Abu Nidal was sentenced to death in absentia by the Palestine Liberation Organization and to life imprisonment by a court in Rome. Since his return to Baghdad, he was said to live in isolation, with only a single bodyguard.