Bill Ackman, founder and chief executive officer of Pershing Square Capital Management LP

Shares of Zoetis fell nearly 2 percent Tuesday following a New York Times report that billionaire hedge fund manager Bill Ackman is selling a stake in the company.

Ackman's Pershing Square Capital Management is trimming 16.85 million shares from his position in Zoetis, with a price range of $46.75 to $47, the Times reported. The sale would bring Ackman's holding to 25 million shares, according to the report. Zoetis's stock is down almost 3 percent this year, closing at $46.56 a share Tuesday.