Carly Fiorina has been fired as CEO of Hewlett-Packard, a development that jumped the share price of the struggling goliath by 12 per cent in early morning trading.

The Palo-Alto-based HP named Robert P Wayman, its chief financial officer, as interim chief executive.

While speculation had grown in recent weeks that her management style was grating on the board, few expected such a dramatic reversal of fortunes for the dynamic Fiorina, widely regarded as one of the top women executives in the world.

Patricia Dunn was named non-executive chairman of the board. Dunn has served as a director with the company since 1998, according to MarketWatch

In her statement, Ms Fiorina cited strategic differences with the board.

According to the board, Ms Fiorina was not fired but stepped down as both CEO and chair of the company`s board -- but her statement seemed to point in another direction.

``While I regret the board and I have differences about how to execute HP`s strategy, I respect their decision,`` she said in a press release.

Ms Fiorina came to HP in July 1999 as CEO and was named president in September 2000.

She pushed the acquisition of Compaq, a merger that has yet to yield substantial dividends and a cause of much bitterness among compteting factions of the board.

First quarter results are due out on 16 February and may provide a clue about the firing, although guidance suggests the company will perform at current consensus analyst expectations of $US2.09 billion in revenues and 37 cents per share profit.

The search for a new CEO will begin immediately.