UBS’s offshore private banking business once employed some 60 private bankers in Lugano, Zurich and Geneva. Prosecutors claimed UBS referred clients to lawyers and accountants who set up secret offshore entities to conceal assets from the I.R.S.

UBS urged some American clients to destroy records and to stash watches, jewelry and artwork that they had bought with money hidden offshore in safe deposit boxes in Switzerland. The bank also encouraged them to use Swiss credit cards so the I.R.S. could not track purchases. In a statement on Wednesday, Peter Kurer, the chairman of UBS, said that “UBS sincerely regrets the compliance failures in its U.S. cross-border business that have been identified by the various government investigations in Switzerland and the U.S., as well as our own internal review. We accept full responsibility for these improper activities.”

Marcel Rohner, the group chief executive of UBS, said in a statement that “it is apparent that as an organization we made mistakes and that our control systems were inadequate.”

In January a senior UBS executive, Raoul Weil, was declared a fugitive, two months after being indicted by a federal judge in connection with the investigation of the bank. Mr. Weil, a Swiss citizen, oversaw the cross-border private banking operations from 2002 to 2007.

UBS had fiercely resisted turning over the names, even after some executives were indicted and implicated in the offshore private banking business. Swiss law distinguishes broadly between tax avoidance, tax evasion and tax fraud. Unlike in the United States, tax evasion is not a criminal offense under Swiss law.

The move by UBS to settle the case, on the eve of a Senate subcommittee hearing next Tuesday on the matter, signals how close the bank came to being indicted for not cooperating with prosecutors. Indictment is a near-certain death knell for corporations.

Of the $780 million that UBS will pay, $380 million represents disgorgement of profits from its cross-border business. The remainder represents United States taxes that UBS failed to withhold on the accounts. The figures include interest, penalties and restitution for unpaid taxes