Nathan Myhrvold, Microsoft’s chief technology officer, said yesterday he is taking a year-long leave of absence after 13 years of service for the Redmond software giant. Myhrvold, who headed Microsoft’s $3bn research unit, will begin his leave on July 1 and plans to join an expedition this summer to hunt for dinosaur remains in eastern Montana. In his absence, the 500- person Microsoft research department will be run by Rick Rashid, VP of research, the company said in a statement. Myhrvold, 39, will return to his position in July 2000.

Formerly a postdoctoral fellow in physics to cosmologist Stephen Hawking at Cambridge University, Myhrvold came to Microsoft in 1986 when it acquired his software company, Dynamical Systems Research. He soon became a top advisor to chairman Bill Gates on trends in technology and had a hand in a number of key projects, including development of the Windows operating system. He founded one of the first research departments at a personal computer software company in 1991 and was named CTO in 1996. Myhrvold denied an article by Time Magazine this week that his leave of absence was prompted by a very private ousting by Microsoft president Steve Ballmer, adding that the move was entirely his own decision. In the statement, the company’s CEO Bill Gates said he plans to draw on Myhrvold’s expertise from time to time while he is on leave. I would rather he continue his work at Microsoft, Gates said, but I support his decision to take a much-needed break and explore his passion for science.