After a little more than a year on the job, Silicon Valley venture capitalist Tom Perkins has resigned from Hewlett-Packard's board of directors.

For Perkins, a founder of the legendary investment firm Kleiner Perkins Caufield & Byers, it was his second stint on HP's board. He had previously served in this capacity from 2002 to 2004 before returning to the job in early 2005, just as former HP CEO Carly Fiorina was being ousted.

HP gave no reason for the resignation, but said it was effective Thursday.

Perkins' history with the computer maker goes back more than 40 years. In the 60s he ran HP's research department and was the first general manager of the company's computer division. He had been a strong supporter of HP's ill-fated 2002 merger with Compaq Computer, another company where he had held a board position.

He co-founded Kleiner Perkins in 1972, but is no longer an active partner in the company.

"He has been instrumental in championing improvements that are leading to a stronger HP," said HP President and CEO Mark Hurd in a statement Friday. "I am particularly grateful for the support he has provided to me over the past year."