Riggs National Bank, the District's largest bank, has been fined $269,750 for failing to report more than 1,000 currency transactions between 1980 and 1985, the Treasury Department announced yesterday.

Treasury officials said that the 1,226 violations of the Bank Secrecy Act occurred under procedures adopted by the previous bank management and no evidence was found that Riggs knowingly engaged in money laundering or criminal behavior in connection with the violations.

Under the act, banks are required to report to the Treasury all currency transactions greater than $10,000. By following large cash transactions, the government hopes to uncover criminal activities such as drug trafficking that involve "laundering" large amounts of funds.

The failure of banks to report currency transactions was underscored earlier this year when the Bank of Boston pleaded guilty to a felony violation and was fined $500,000 for failing to report the transfer of $1.22 billion in cash from European banks.

Since then, Crocker National Bank of San Francisco paid $2.25 million in fines for failing to report nearly $4 billion in large cash transactions, which a Treasury official said appeared to be the byproduct of large-scale money laudering by international heroin traffickers.

Unlike Crocker, Riggs voluntarily and promptly brought the problems to the attention of the Treasury, the department said. Riggs also cooperated with the government and conducted an internal investigation of its Bank Secrecy Act compliance, the Treasury Department said in a statement.

"We view Bank Secrecy Act reporting failures, for whatever reason, as extremely serious," said David D. Queen, acting assistant secretary for enforcement and operations. "Failures to file timely currency reports deprive Treasury of potentially useful law enforcement information."

"We did an extremely extensive audit of the thing," said George Beveridge, spokesman for Riggs. "Failures to report appeared to have resulted from misunderstanding of what the filing requirements were."

Most of the transactions did not involve receiving cash from individuals but concerned the bank's purchases and sales of foreign currency with financial institutions and foreign currency brokers, Beveridge said.

More than 60 financial institutions have disclosed reporting violations to the government this year, Treasury officials said.

The agreements to pay fines have come about as part of a Treasury campaign to crack down on suspected money laundering through U.S. financial institutions.