Mick McGuire learned at the feet of the Pershing Square founder.
BNY Mellon on Tuesday came under intense, public fire from shareholder Marcato Capital Management LP, which called for the ousting of the custody bank’s chairman and chief executive, Gerald Hassell, and cost cuts. BNY Mellon had just avoided a potential battle when it gave larger activist firm Trian Fund Management LP a board seat in December. Companies often face challenges from more than one activist. But it is unusual for an activist investor to take shots at a company when another is already trying to make a difference in the boardroom...Its attack Tuesday on BNY Mellon marks the second time in the past month that it has gone on the offensive against a company that has given a board seat to another activist. Last month, it called for more share repurchases and chastised the board of auction house Sotheby’s , in which Third Point LLC’s Daniel Loeb gained board seats for himself and two allies last May. Sotheby’s said it welcomes dialogue but is concentrating on finding a new chief executive before it determines capital returns. Marcato is run by Mick McGuire, a protégé of activist William Ackman.