The IT services provider is looking to help clients shift to cloud platforms such as Microsoft Azure, Amazon Web Services, and Google Cloud.
The 22-year company veteran replaces Martin Schroeter, who becomes senior vice president of global markets.
Investors express their impatience with the pace of IBM's turnaround effort by sending its shares down nearly 5% to $161.84.
The stock falls 5% despite stronger-than-expected growth in cloud computing and other businesses IBM hopes will fuel a turnaround.
In addition, IBM expects 2014 operating earnings per share to decline as much as 4% from 2013.
