hree Arabs received prison sentences of 30 to 35 years today after a jury convicted them of the attempted assassination of Israel's ambassador to Britain, Shlomo Argov, who was critically wounded outside a London hotel last June.

The men were members of a Baghdad-based Palestinian group that had been sent to London to attack Jewish targets, the prosecution said. The Argov shooting, one of several attacks on Israeli diplomats in Europe last year, was cited by Israel when, three days later, it invaded Lebanon and demanded the withdrawal of all Palestinian forces there.

The three--Hassein Said, 23, and Marwan Banna, 20, both from Jordan, and Nauoff Rosan, 36, from Iraq--were convicted in London's Central Criminal Court. Said, who fired the shots, was given a 30-year sentence as was Banna, driver of the getaway car. Rosan, who was also in the car and who the prosecution described as the leader of the group, received a 35-year term because, the judge said, he is "older and deserved more substantial punishment."

Argov, 52, who has returned to Israel, was shot in the head and is now paralyzed except for slight movement in his left hand, the jury was told. When investigators visited him, he was able to understand questions but found it difficult to speak in reply. Argov, who once served as minister in Israel's embassy in Washington, is being treated in a Jerusalem hospital.

Prosecutors said the three terrorists were members of the Palestine National Liberation Movement, a breakaway faction of the Palestine Liberation Organization headed by Sabri Banna, also known as Abu Nidal. Abu Nidal is a bitter foe of PLO leader Yasser Arafat and has been sentenced to death in absentia by Arafat's Fatah organization. He has been blamed for several international terrorist attacks.

The three Arabs arrived in Britain in 1980 or 1981 and took language courses while preparing, the prosecution said, "for acts of assassination or sabotage."

"They spent considerable time collecting information about Jewish interests and personalities in London," prosecutor Roy Amlot said, "including top secret details of security at the Israeli Embassy."

Police found hit lists in their apartments of prominent British Jews and Jewish institutions, including kindergartens and synagogues. Also discovered was a cache of weapons, including four Soviet-made grenades.

In passing sentence, Judge William Mars Jones said that the men were clearly intent on a "sustained and bloody campaign of terror" and he told them, "We will not tolerate gangs of terrorists operating in this country or their campaigns of violence being conducted in this capital city."

Argov was shot as he was leaving a black-tie dinner at the Dorchester Hotel in central London on June 3. Said fired a Polish submachine gun at the ambasador's head and attempted to flee by car. But Argov's British police bodyguard, Colin Simpson, chased Said down an adjoining street and shot him in the neck.

The other two sped away in an automobile, but their license number was noted by a security supervisor at the nearby Hilton Hotel. They were apprehended in south London within hours of the attack.

The Arabs listened impassively to the sentencing. They had professed innocence throughout the investigation and trial. Said's lawyer said his client just happened to be on the dark street as Simpson ran after the assailant and was mistakenly shot. Rosan's lawyer said, "He will undergo the sentence which awaits him, but his spirit remains unshaken."