Allen & Overy (A&O) has ramped up its New York presence by hiring a Manhattan public prosecutor as a litigation partner.

David Esseks will join the magic circle firm as a partner from the Southern District of New York’s US Attorney’s Office, where he headed up the securities fraud unit.

As an assistant US attorney, Esseks was involved in some successful high-profile securities fraud prosecutions, including those of executives at Worldcom and Refco.

Essek’s last spell in private practice ended in 1994, when he left his associate position at New York firm Lankler Siffert & Wohl to join the US Attorney’s Office.

He will join litigation partner Robert Knuts at A&O. Knuts joined last September from Day Berry & Howard (, 12 September 2006), having previously worked as senior trial counsel in the New York office of the Securities and Exchange Commission (SEC) where he led investigations into securities law violations and worked with prosecutors on criminal proceedings.

Three other former assistant US attorneys have also found their home at A&O’s New York office, including US head of litigation Michael Feldberg. Feldberg said: “We are thrilled to welcome David to Allen & Overy. His experience will add to our ability to advise our clients in the securities regulatory area.”

New York is a priority area for managing partner David Morley, who would like to see the office grow in the coming months. Esseks is the second international partner hire in a week for the firm, coming after the hire of Freshfields Bruckhaus Deringer’s Italian banking head Stefano Sennhauser on 24 October.