The head of Adobe's Platform Division, which oversees Flash Player, PDF (Portable Document Format) and other technologies, has left to join a Silicon Valley private equity firm.

John Brennan, who was senior vice president of the division, also was a driving force behind the acquisition of Macromedia in 2005. He is leaving to become a managing director of Silver Lake Sumeru, a new business of Silver Lake, a leading technology-focused private equity firm in Menlo Park, California.

Brennan joined Adobe in 2004 as senior vice president of corporate development and strategy, handling planning, mergers and acquisitions, and in 2005 he led the Creative Professional Business Unit, Adobe's largest division. In his last Adobe post, running the Platform Division, Brennan also was responsible for the Adobe Flex open-source Web development framework and the Adobe AIR cross-OS application runtime.

Adobe makes many of the most popular applications for multimedia creation, including Photoshop, Illustrator, Premiere Pro and After Effects, but is best known for the ubiquitous PDFs and the Acrobat platform that creates them. The Macromedia purchase gave Adobe a strong position in development and design tools for building rich Internet applications. Flash, which came from the Macromedia deal, is widely used on the Web and forms the basis for video playback on Google's YouTube and other sites.

In December, former CEO Bruce Chizen handed over the reins to longtime Adobe executive Shantanu Narayen in what he characterized as a personal decision. Financial performance did not appear to be a factor: At the same time that move was announced, the company said revenue in its fiscal fourth quarter would exceed expectations. In fiscal 2007, the company earned US$1.21 per share, up from $0.83 per share the previous year.

Adobe officials were not immediately available for comment.

Prior to joining Adobe, Brennan was senior vice president of worldwide small and medium-size business operations at Hewlett-Packard. He previously had run HP's corporate development. Brennan, 43, has a bachelor's degree from Yale University and a master's degree from the University of California at Berkeley.

Silver Lake Sumeru will invest in medium-sized companies. Silver Lake has attracted several high-level technology executives over the years, including Ed Zander from Sun Microsystems and Michael Capellas from Hewlett-Packard. Both later went on to lead other companies.