Carly Fiorina, HP’s chair and chief executive is leaving the company, weeks after it was suggested that the HP board wanted to take away some of her day-to-day responsibilities.
"While I regret the board and I have differences about how to execute HP's strategy, I respect their decision," said Fiorina.
In 2002, Fiorina pushed through the merger of HP and Compaq which was aimed at putting together a portfolio of technologies and products, spanning consumer and corporate applications, which would be different from that offered by other suppliers.
She also set out to build up HP’s services arm into a rival to IBM Global Services, EDS and other industry giants.
Last October Fiorina said, "Compaq, while it was a huge merger, was a tactic, not a strategy. The challenge now is to use what we have built."
Despite her efforts, Wall Street analysts felt that the merger never fully delivered what was promised.
HP revealed last August that problems with its SAP order processing and supply-chain deployment resulting in a $400m (£220m) revenue shortfall in the company's enterprise system group. Peter Blackmore, executive vice-president of HP's customer solutions group, left the company shortly after the problems were disclosed.
Robert Wayman, HP's chief financial officer, has been named chief executive officer on an interim basis. Wayman will retain his CFO responsibilities.
Patricia Dunn, an HP director since 1998, has also been named non-executive chairman of the board.
"Carly Fiorina came to HP to revitalise and re-invigorate the company. She had a strategic vision and put in place a plan that has given HP the capabilities to compete and win," said Dunn.
"We thank Carly for her significant leadership over the past six years as we look forward to accelerating execution of the company's strategy," she said.
Last month US newspaper reports claimed that the HP board wanted to take away some of Fiorina’s day-to-day responsibilities in attempt to take the pressure off her and speed company changes designed to improve the performance of the group.
The reports were described by HP at the time as speculation and Fiorina herself said she had no intention of watering down her role.
The company plans to report its first quarter financial results on 16 February.