2006 set a record for mergers and acquisitions worldwide. Deals totaled $3.79 trillion 38% higher than in 2005 and 55 of the transactions were valued at more than $10 billion each according to data from Thomson Financial. Private equity firms were major movers in this trend responsible for 20% of global M&A activity and 27% of activity in the U.S. according to Thomson. How long will this M&A binge continue and when it does come to an end what will be the factors behind the retreat? Knowledge at Wharton asked management professor Harbir Singh an expert on corporate acquisitions and restructuring to offer his views on the M&A landscape.