Updated: VMware chief executive replaced

VMware, the leader in the growing virtualisation market, unexpectedly announced today that co-founder, president and chief executive Diane Greene has resigned and will be immediately replaced by Paul Maritz.

VMware did not give the reason behind what it called a "change in leadership", but did say that Maritz would be named to the board of directors and that the appointment would be made immediately.

VMware was spun-out of EMC earlier this year, but that firm still owns the majority of its shares. Joe Tucci, chairman of VMware's board of directors and the head of EMC, said in a statement: "As one of the founders and the leader of VMware, Diane guided the creation and development of a company that is changing the way that people think about computing. The board thanks her for her considerable contributions to VMware and wishes her every success in the future."

The news comes after VMware reported that its full year revenue growth will be "modestly" below the 50 per cent growth it previously forecast. Full results for the most recent quarter will be released 22 July.

Microsoft finally joined the virualisation market this year with its Hyper-V product, and has already put a dent in VMware's market share.

Greene's successor Maritz previously worked at Microsoft for 14 years, where he managed the development and marketing of products like Windows 95. He retired in 2000 and several years later founded start-up Pi.

Tucci said: "Paul [Maritz] is a leader in the software industry. He has decades of experience building one of the greatest franchises in software history, Windows. Paul was instrumental as part of the core executive leadership team in building much of Microsoft's success."