Michele Sindona, the Italian Financier who faces trial next month for his role in the largest bank failure in U.S. history, has disappeared.

Lawyers for Sindona, both here and in Rome where he also faces charges, said they think Sindona has been kidnapped. Sindona has been missing since last Thursday.

But a spokesman for the New York Police Department said the agency has no reason yet to suspect Sindona has been kidnapped.

"We're carrying him as a missing person," the police spokesman said. "Who knows, he might have taken off."

Sindona, who has been free on a $3 million personal recognizance bond, was indicted last March on 99 counts of fraud and perjury in connection with the 1974 failure of Franklin National Bank. Before its collapse, Franklin National was the 19th largest bank in the United States.

Sindona has been living in luxury at the Pierre Hotel in Manhattan's upper East Side, in an apartment owned by his wife. He has been fighting extradition to Italy, where officials want to charge him with taking $225 million from several banks he owned there.

Last month, U.S. District Court Judge Henry F. Werker dismissed the government's effort to extradite Sindona to Italy to stand trial on charges that he looted one of his Italian banks, Banca Privata.

Werker said that the banker's activities here and in Italy should be considered "one massive fradulent scheme." Forcing Sindona to face trial both in Italy and in the United States would be double jeopardy, Werker reasoned.

Marvin Frankel, a former federal judge who is one of Sindona's lawyers, said Sindona's New York secretary called him a little after 9:30 a.m. last Friday. Frankel said she told him that she received a call from a man with a foreign accent who said, "Listen carefully. This is important. We now have Michele Sindona as our prisoner. You will hear from us."

Frankel said today, however, that he is not aware of any further contact from Sindona's alleged abductors and has not heard of any ransom demands.

The Federal Bureau of Investigation said that the agency is aware that Sindona's "Whereabouts are unknown,"but said the agency has not fornally entered the investigation. A spokeman said the agency is trying to determine whether a federal law has been violated.

Police officials say privately that there is reason to be skeptical about Sindona's kidnapping.They note Sindona is a man of great wealth who has the wherewithal to go anywhere in the world. With a federal trial coming up September 10 and charges hanging over his head in his native Italy, he might have chosen to flee.

The FBI and the New York Police Department asked Sindona's lawyers here and in Italy to hold off on making any statement about Sindona's disappearance last Friday.

Police officials apparently wanted to hold off making any announcement about Sindona so as not to encourage cranks from making ransom calls.

Frankel, Sindona's New York lawyer, said that the financier's Italian lawyers put out a statement today after rumors began to circulate in Italy about Sindona's disappearance. Frankel said that from the facts available to him, he believes Sindona has been kidnapped.

Last March a federal grand jury here handed down a 99-count indictment charging that Sindona looted deposits of two banks he controlled in Italy in order to buy effective control of Franklin National Corp., the holding company that owned Franklin National Bank.

Then the grand jury charged, Sindona took $45 million out of Franklin and falsified the bank's records to cover that up.