Kweku Adoboli's, the "mastermind" behind $2.3 billion in trading losses, is not the only UBS head that will roll as a result of the fraud.  The 'head' of the investment-banking division, Carsten Kengeter, long considered the top choice to succeed Oswald Grübel as UBS CEO, is now watching that chance slip away. Grübel came out of retirement in February 2009 to help turn around UBS.  He's said he plans on seeing his restructuring plan through, but is expected to leave once it's completed in around 2013.  Mr. Kengeter joined UBS in 2008 and quickly impressive the bank's executives with his results in the fixed-income unit.  However, slacking performance in the last year and the new Adoboli case have done much to erode Mr. Kengeter's ascendancy towards the chief executive position at the bank. [WSJournal, 9/17/11]