Filing: Ackman sold about 5M ADP shares and options after defeat

• With a board battle lost, Bill Ackman's Pershing Square sold about 5M shares and call options in Automatic Data Processing (NASDAQ:ADP) in December.
• That leaves the firm with about a 7.2% stake, according to an SEC filing, down from 8.3%.
• Ackman's said he might go back to the proxy-fight well in a year if he doesn't see dramatic improvement in operations.