The alleged financier for a group of Argentine terrorists was indicted yesterday in New York in connection with a swindle more than $30 million. He was reportedly killed in a 1976 plane crash, but is believed to be alive.

David Graiver, the supposedly dead South American financier, and four other officials of the now defunct American Bank and Trust Co. of New York were charged by a state grand jury with conspiracy, misappropriating funds and falsifying bank records in an international financial scheme involving six countries.

Manhattan District Attorney Robert M. Morgenthau said that most of the funds involved were loaned from the New York bank to a Belgian bank to a number of companies controlled by the Graiver family.

Graiver was identified as having been killed in a plane crash in Mexico in August 1976, just before New York state banking authorities closed American Bank and Trust. He is said to have invested millions of dollars in buying into that bank.

Stephen Shiffrin, an assistant district attorney in Morgenthau's office, said in a telephone interview yesterday that the grand jury had reason to believe that Graiver is still alive. "We're too busy up here to go around indicting dead men," he said.

He refused to disclose the evidence that showed Graiver was alive. "We're looking for the man. We can't comment on our leads. That might spook him," Shiffrin said.

Graiver's alleged connections with the Montoneras guerrilla group caused a sensation in Argentina a year ago. The ruling junta began circulating stories that he served as a banker and investment counselor for the guerrillas.

It was charged that he tookd Montonero money from bank robberies and kidnap ransoms and invested it in bank overseas.

He even paid the guerrillas monthly dividends to bankroll their continuing operations, the junta alleged.

Shiffrin declined to say whether the New York investigation uncovered evidence that Gravier was laundering any guerrilla money through the New York bank to investments in Belgium and other countries.

"All that is unreleated to the charges," he said. "We don't say in the indictment where the money came from or what happened to it after it left the bank."

The indictment charges specifically that Gravier and other officials of the New York bank illegally made a series of loans to Gravier-controlled entities in excess of amounts permitted by state banking laws.

Indicted with Gravier were Saul Kagan, Jean Wolf, Edmun A. Fleckenstein and Torleaf Benestad, all officials of the New York bank.

The investigation began in August 1976, with the collapse of American Bank and Trust, said to be the fourth largest bank failure in U.S. history.

The Belgian bank involved, Banque Pour l'Amerique du Sud (BAS), was owned by Gravier and his father. It too, went bankrupt, and its top official has been charged with related financial crimes in Belgium.

When the allegations of guerrilla connections surfaced last year, members of Gravier's family in Argentina were arrested.