Why are so many M&A deals being pulled? By: CNBC.com News June 04, 2014 at 07:51 AM EDT The value of potential takeovers yanked from the market is at its highest level since the height of the global credit crisis in 2008. Read More >> Related Stocks: Alstom S.A. Astrazeneca Plc ADR Bhp Billiton Plc ADR Pfizer Rio Tinto Plc ADR