The head of mergers and acquisitions at the Credit Suisse investment bank has decided to leave. To make matters worse, the CS veteran is joining a bank with which the Swiss institute only just concluded a deal.

David DeNunzio 160David DeNunzio (pictured left) has been at Credit Suisse (CS) for a quarter of a century. Now he had decided it is time for something new: the Swiss bank's top dealmaker will join Well Fargo, according to a report by «Reuters». The U.S. retail bank only last year agreed to purchase CS' wealth management in the U.S. DeNunzio will become global head of mergers and acquisitions.

DeNunzio's contacts will come in handy for Wells Fargo, which is currently expanding its M&A business. Based in New York, DeNunzio was global chairman M&A at the investment bank of Switzerland's No. 2 bank. DeNunzio joined the mergers business First Boston Corp. in 1989, a year before CS acquired the bank.

CS didn't comment the departure of DeNunzio, according to «Reuters». It isn't known who it will entrust with his replacement.

The bank has been hit by a series of high-profile departures in the U.S. They came as the bank embarked on a strategic rethink announced in October. For instance, most of the bank's leading technology experts left the bank recently.