ATHENS, Greece (AP) _ The Socialist government of Prime Minister Andreas Papandreou survived a censure motion early Tuesday by 155 votes to 123 votes in the 300-member Parliament.

The roll call was held at Monday midnight after a three-day debate on the motion presented by the conservative New Democracy opposition party.

New Democracy leader Constantine Mitsotakis accused the government of ''undermining the institutions and democracy.'' He also pointed to a banking scandal in which Papandreou and senior Cabinet ministers were accused of raking in millions in payoffs.

Deputies from Papandreou's Panhellenic Socialist Movement cheered and applauded when Speaker Yiannis Alevras announced the voting result. The Socialists control 157 seats in the single-chamber Parliament.

After the vote, Papandreou announced that three Socialist deputies who abstained would be dismissed from the party.

Of 278 deputies in the chamber for the vote, 123 voted for censure. The Socialists picked up a vote from an independent deputy.

New Democracy, with 111 seats, received support from independents and a small, conservative splinter group. The Communists, with 10 seats, abstained.

In a speech during the debate, Papandreou indirectly accused the CIA of helping the Greek banker involved in the multimillion-dollar scandal to flee the country.

The prime minister rejected a U.S. State Department statement denying that a self-proclaimed CIA agent ever worked for the intelligence agency.

''The statement issued by the United States Embassy that Mr. Mailis was not part of the CIA is unacceptable,'' Papandreou said.

The purported agent, Tom Mailis, told a parliamentary fact-finding committee last week that banker-publisher George Koskotas was a CIA agent trying to undermine Greece.

Mailis has not been available for further comment.

The State Department, in a statement issued Sunday through the U.S. Embassy in Athens, said that ''neither he nor the others he reportedly has alleged to work for the CIA now work or ever have worked for the CIA.''

''In whose interest was it to allow Koskotas to flee Greece? In the United States he has the entire media available to him to attack the government. So again I ask, in whose interest was it to make him flee?'' Papandreou said.

He reiterated a call for Koskotas' immediate extradition from the United States and threatened ''painful'' consequences if Koskotas was not sent to Greece before June elections here.

''I will tell you about the consequences before the elections and they will be painful,'' he said.

Last week, Papandreau hinted at consequences for the United States. On Saturday he made a reference to his government's decision to shut down one of four U.S. military bases in Greece. He said talks on a new bases agreement were continuing but that ''their (bases') time of stay in Greece is running out daily.''

Koskotas fled Greece last November after being indicted in a $200 million fraud, forgery and embezzlement scandal.

He was arrested in the United States and is in a Salem, Mass., jail awaiting an extradition hearing.

Koskotas, 34, has alleged that Papandreou and senior Cabinet members authorized plans to siphon millions of dollars from the Bank of Crete while Koskotas was chairman. He also claimed they received millions of dollars in payoffs.

Most of his allegations were reported in the March 13 issue of the U.S. news magazine Time.

Mitsotakis, leader of the opposition New Democracy Party, accused Papandreou of not replying to the allegations and described his charges of CIA involvement ''a children's story.''

''It is not the foreign and domestic centers that are destabilizing Greece,'' Mitsotakis said, adding that ''you (Papandreou) are the one that has turned Greece into a banana republic.''

Mitsotakis said his party submitted the censure motion because the government was ''undermining the institutions and democracy.''

He also charged that Socialist officials were ''deeply involved'' in the Koskotas affair.

The conservative also accused Papandreou's government of being involved in illegal arms shipments to the Sandinista government in Nicaragua and to Iran and Iraq when those two countries were at war.

''I believe the arms scandals are much larger than the Koskotas affair,'' Mitsotakis said.

Papandreou's only response was to say that ''Mr. Mitsotakis went overboard tonight with his lies and slander.''