UBS AG will hand over some 4,450 names of U.S. account holders as part of a U.S.-Swiss tax-evasion settlement and investigation that could produce in total 10,000 account identities, according to people familiar with the situation.

Details of the settlement, which was reached earlier this month, are expected to be provided over the next half-hour. Swiss and Internal Revenue Service officials plan to provide those details, these people said.