Pershing Square makes adviser Fraidin its vice chairman, noting his experience with mergers

Hedge fund Pershing Square Capital Management on Tuesday named Stephen Fraidin as its vice chairman, touting his experience in mergers and acquisitions.

Fraidin has been with the Manhattan law firm Kirkland & Ellis LP since 2003, and he has been on Pershing Square's board of advisers since its founding in 2004.

Pershing Square, which is run by activist investor Bill Ackman, said Fraidin was an adviser on its unsuccessful bid for Botox maker Allergan and has been a key adviser on other important investments.

The company also announced the departure of Chief Legal Officer and investment team member Roy Katzovicz, who has worked at Pershing Square since 2006. Ackman said Katzovicz will remain an advisor to the firm.

Pershing Square, the largest owner of Allergan shares, and Canadian drugmaker Valeant Pharmaceuticals teamed up to make an offer to buy Allergan in 2014. They offered as much as $53 billion, but Allergan ultimately accepted an offer from Actavis PLC worth $62.5 billion.