Pershing Square Says Doyle Leaving Firm Amid Novocure Demands

William F. Doyle, the chairman of Novocure Ltd. who joined Pershing Square Capital Management part-time in September 2013, is leaving the activist hedge fund.

Doyle became an official member of Pershing Square’s investment team in October 2014, according to an investor letter dated May 11.

“The demands of overseeing Novocure and managing its relationship with its shareholders and other stakeholders have made it infeasible for Bill to continue as a member of the investment team,” Bill Ackman, Pershing Square’s founder, said in the letter.

In addition to Doyle’s duties at Novocure, where he recently took the role of executive chairman, he’ll be working part-time at Table Management, according to the letter. Table is “an entity which oversees private investments for my family,” Ackman wrote.

Ackman reiterated that Doyle, who represented Pershing Square on Zoetis Inc.’s board since Feb. 2015, won’t stand for re-election.

“We no longer feel that our presence on the board is required as the company continues to generate strong progress as evidenced by first-quarter results,” Ackman wrote.

Pershing Square funds own a 5 percent economic stake in animal-health company Zoetis, down from 8.6 percent after a recent block sale, the letter shows.

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