UPDATE 1-Key player in Pershing Square's Valeant bet leaving firm

(Adds details on Doyle's tenure at Pershing Square (NYSE:SQ))
By Svea Herbst-Bayliss
LAS VEGAS, May 11 (Reuters) - William Doyle, a key figure in
Pershing Square Capital Management's controversial investment in
battered drug company Valeant Pharmaceuticals (NYSE:VRX) VRX.TO , is
leaving the hedge fund, its founder, William Ackman, told
investors on Wednesday.
Doyle joined Pershing Square's investment team in October
2014, but had also been involved in other projects including
advising cancer therapy company Novocure NVCR.O , which listed
its stock last year.
"The demands of overseeing Novocure and managing its
relationship with shareholders and other stakeholders have made
it infeasible for Bill to continue as a member of the investment
team," Ackman wrote in a letter to investors that was seen by
Reuters.
Novocure said on Wednesday that Doyle will be the company's
executive chairman after having already been a board member.
Ackman said Doyle will also spend time at Table Management, an
entity that oversees private investments for Ackman's family,
Ackman wrote in his letter.
Doyle introduced Michael Pearson (LON:PSON), the former CEO of Valeant,
and Ackman, the billionaire activist investor, in early 2014 and
a year later Ackman's Pershing Square invested in the Canadian
drugmaker.
In 2015, Ackman called Valeant his best idea but it has
become the firm's biggest ever loser. Valeant's stock has
tumbled 85 percent amid scrutiny over its accounting and pricing
practices, ultimately prompting Ackman to join Valeant's board
and forcing Pearson to leave his position as CEO.
Doyle was friends with Pearson from their days as
consultants at McKinsey and Doyle knew Ackman through Harvard
Business School. Doyle joined Pershing Square's investment team
shortly after brokering the initial meeting and helped oversee
science-oriented investments.
Last month, Pershing Square said Doyle would not stand for
reelection as a board member at animal health company Zoetis Inc (NYSE:ZTS)
ZTS.N . Earlier this week the fund sold a chunk of its
investment in the company.
Doyle's exit marks the second departure of a Pershing Square
investment team member in five months. In January, Paul Hilal,
who has been friends with Ackman since college, left the firm.