Former UBS general counsel David Aufhauser, who resigned last year following allegations of involvement in the bank’s alleged sale of auction-rate securities, has rejoined his former firm Williams & Connolly.

Aufhauser – a former managing director of the Swiss bank and general counsel of the US Department of the Treasury – last October settled charges with New York attorney general Andrew Cuomo that he engaged in insider trading at UBS, agreeing to pay $6.5m (£3.9m).