Proskauer Rose has settled a malpractice lawsuit brought by a former client, Overseas Shipholding Group, which claimed the firm’s advice cost the oil tanker company hundreds of millions of dollars in tax liability.

In a statement late Friday, Proskauer said it was confident it would have ultimately prevailed, based on the discovery record. “Doing so, however, would involve substantial additional cost. Accordingly, the firm reluctantly agreed as part of the settlement to pay an amount to OSG that is substantially less than the out-of-pocket cost of continuing the litigations,” Proskauer said.