Soros Fund Management is withdrawing its money from William Ackman's Pershing Square Capital Management due to performance, a person close to the matter said on Thursday.
Pershing is in the process of returning the money, less than $250 million, to Soros by early 2014, the person said.
Ackman's Pershing Square lost 2.2 percent in July but is still up 3.8 percent year-to-date, three investors told Reuters earlier this week.
(Read more: Ackman's Pershing Square losses 2.2% in July)
The redemption move by Soros has been in motion for quite some time, the person said, and comes during a bitter battle over nutritional-supplement company Herbalife, with Soros and Ackman on opposite sides.