ADP Takes Swipe at Ackman, Setting Stage for a Fight
Human-resources software firm rejects Pershing Square's request to extend deadline to nominate directors
Updated Aug. 4, 2017 7:20 pm ET
Automatic Data Processing Inc. fired an unusual broadside against activist investor William Ackman Friday, taking the first strike in what is shaping up to be a nasty fight over the human-resources software giant's leadership.
ADP said early Friday that Mr. Ackman had taken a stake in the company and revealed he was seeking to throw out half the company's board and replace Chief Executive Carlos Rodriguez.