WASHINGTON — IRS Commissioner Doug Shulman says Swiss banking giant UBS will give his agency the details of 4,450 client accounts suspected of holding undeclared assets.

The deal to end a contentious international lawsuit between U.S. tax collectors and Swiss bankers was announced this morning.

Shulman said in prepared remarks that the deal will give the IRS thousands of long-sought account names and is expected to provide even more UBS clients who voluntarily disclose their financial details to the agency. UBS has an estimated 52,000 accounts of U.S. customers.

Shulman said the 4,450 accounts were the ones most suspected of containing undeclared assets.

The two sides told a federal judge last week they had reached a tentative agreement, but the details were not released until today.