Skadden Arps Slate Meagher & Flom has taken Cadwalader Wickersham & Taft's head of antitrust along with two of his partners.
The fallout at Cadwalader following head of antitrust Steve Sunshine's departure is expected to extend to several associates, who are expected to join him at Skadden.
Cadwalader's antitrust capability is now limited to three litigation specialists in its New York headquarters.
Sunshine will join Skadden's Washington DC office while partner Jessica Biggio and Matthew Hendrickson, the latter joining Skadden as of counsel, will join the firm's office in New York.
Sunshine and Biggio were at Cadwalader for less than two years, joining in March 2005 from Shearman & Sterling, where Sunshine was also head of antitrust.
He jumped ship from Shearman to Cadwalader for a reputed $3m (£1.53m) remuneration package, which sealed the deal over other contenders, including Willkie Farr & Gallagher and Milbank Tweed Hadley & McCloy.