Thelen Reid & Priest has lost five partners to LeBoeuf Lamb Greene & MacRae.

The departures coincide with partner Stephen O’Neal becoming managing partner. He also replaced Thomas Igoe as partnership chairman, adding international relationships to his duties.

Those joining LeBoeuf are: former New York managing partner Jonathan Siegfried and fellow litigator Lawrence Hirsh, corporate partner Glynna Cristian, former vice-chairman of Thelen’s business department Eric Cowan, who will now head LeBoeuf’s telecoms practice, and Richard Rubin, who joins the Washington DC telecoms department.

In April, the firm also lost project finance attorney Linda Grant Williams to Pillsbury Winthrop Shaw Pittman, the former co-chair of Thelen’s corporate and securities litigation group Richard Swanson and fellow partner Veronica Rendon, both to Arnold & Porter. Thelen partner Marianne Rosenberg, the one-time managing partner of Linklaters‘ New York office, has quit for French firm Gide Loyrette Nouel.