Haas' last day will be June 1, and a search for his replacement is already under way, HP said in a prepared statement. Bethany Mayer, vice president of worldwide marketing and alliances for Enterprise Servers, Storage and Networking, will become the acting head of the networking business.

Haas' departure caps a period of significant expansion for the HP Networking Division but also comes after several other management changes that took place in the wake of Leo Apotheker's arrival as CEO. Last month, HP appointed Martin Homlish, Apotheker's former colleague at SAP, as executive vice president and chief marketing officer. The company also recently named Thomas Hogan as the sales, marketing and strategy chief for its enterprise business and appointed new regional directors for Asia Pacific, the Americas and EMEA (Europe, Middle East and Africa).

The acquisition of 3Com in April 2010 brought HP a wide range of routing, security and other products that could make it an across-the-board rival to Cisco. Haas oversaw that acquisition after being named senior vice president and general manager of the HP Networking Division in 2008. Previously he had been senior vice president, chief strategy officer and global head of corporate mergers and acquisitions for HP from 2003 to 2008.

However, HP hasn't yet derived all the advantages it might from that buyout, said Yankee Group analyst Zeus Kerravala.

"I don't think the acquisition of 3Com ... has been as simple as they thought it would be," Kerravala said. The task of integrating storage specialist 3Par, which was also acquired last year, may be compounding HP's challenge, he said.