The news last Wednesday of Kenneth Lewis’ exit announcement caught many inside Bank of America off guard. Among them appeared to be Thomas Montag, the bank’s president of global banking and markets and one of several high-ranking executives considered potential successors to the 62-year-old Lewis.

"WHAT!!!!!!!!!!!!!!" wrote Thomas Montag in a 5:37pm email, according to people familiar with the email. That was just minutes after the Charlotte, N.C., bank put out its news release disclosing Lewis' decision to step down at the end of 2009.