Hewlett-Packard has ousted chairman and chief executive Ms Carly Fiorina, one of the most powerful women in US business, after disagreements with the company's board over strategy.
Shares of HP, a component of the Dow Jones industrial average, rose $2.30, or 11.4 per cent, to $22.44 in pre-market trade on the Inet electronic brokerage system following news of Ms Fiorina's departure.
"While I regret the board and I have differences about how to execute HP's strategy, I respect their decision," Ms Fiorina said a statement.
"HP is a great company and I wish all the people of HP much success in the future."
Mr Robert Wayman, HP's chief financial officer, was named CEO on an interim basis and appointed to the board of directors of the computer and printer maker.
Mr Wayman rose through the ranks at HP after joining the company in 1969. The company said a search for a new CEO was under way.
Ms Patricia Dunn, vice chairman of Barclays Global Investors and a member of HP's board since 1998, was named non-executive chairman of the board. Ms Fiorina, who joined HP in 1999, became the lightning rod of criticism among investors and the Silicon Valley establishment for pushing through HP's merger with Compaq Computer in 2002.