Carleton S. Fiorina, among the most powerful women working in corporate America, stepped down as the chief executive of the giant computer maker Hewlett-Packard, the company announced on Wednesday. The resignation, which came on Tuesday evening, brings to a close a rocky tenure for Fiorina, whose charisma and aggressive, top-down leadership style made her a highly visible personality in the consumer electronics industry and the target of some criticism during her five-year stint with the company. ‘‘While I regret the board and I have differences about how to execute HP’s strategy, I respect their decision,’’ Fiorina said in a statement. ‘‘HP is a great company and I wish all the people of HP much success in the future.’’ Robert P. Wayman, Hewlett-Packard’s Chief Financial Officer and a 36-year employee of the company, was named Chief Executive on an interim basis and was appointed to the company’s board. Patricia C. Dunn, a director at Hewlett since 1998, was named non-executive chairman of the board. ‘‘This is not a change related to strategy,’’ Dunn said in a conference call with industry analysts and investors. ‘‘This is a changed based on a desire to accelerate that strategy. We think that requires hands-on execution.’’ She added: ‘‘These things always seem precipitous when they occur. But the board has been deliberating the company’s performance, and the CEO’s performance, for quite some time.’’ Dunn said no other changes in management were expected at this time and that the company would continue to operate essentially the same way. ‘‘The board is firmly committed to the business strategy that is in place,’’ she said. Wall Street signalled its approval of Fiorina’s resignation. Hewlett’s shares were trading up 93 cents, or 4.6 per cent, at $21.07 around midday today on the New York Stock Exchange. The decision to remove Fiorina comes after a rocky six months for Hewlett. Last August, the company missed its financial forecasts for the company’s third quarter, sending its shares tumbling. The company’s fourth-quarter financial results were in line with Wall Street’s expectations, but there continued to be pressure on Fiorina from shareholders to break up the company. Fiorina acknowledged in December, at a meeting with Wall Street analysts, that she had three times discussed a break-up with the Hewlett board but ultimately decided against it. ‘‘There are no plans to break up the company,’’ a company spokesman, Michael Moeller, said. Hewlett plans to report first-quarter financial results on February 16, after the stock market close. Dunn said the decision to seek Fiorina’s resignation was not connected to the first-quarter results. The rise & fall of Carly Fiorina NAME: Cara Carleton Sneed Fiorina. BIRTHDATE: Sept. 6, 1954. EDUCATION: • Bachelor’s degree in medieval history and philosophy, Stanford University, 1976 • Master’s in business administration degree, University of Maryland, 1980 • Master’s of science degree in management, Massachusetts Institute of Technology, 1989. EXPERIENCE: (i) Saleswoman, marketing posts and other executive positions, including head of North American network systems, at AT&T Corp, 1980-1996. (ii) Helped lead spinoff of equipment/research division into Lucent Technologies Inc in 1996. (iii) President, Lucent’s global service provider business, 1998-1999. (iii) Named chief executive and president of Hewlett-Packard Co in 1999 and given the title of chairwoman in 2000. (iv) Resigned from the company Feb 9, 2005, citing differences with the board over executing its strategy. She is a board member of Cisco Systems Inc FAMILY: Husband, Frank Fiorina; two stepdaughters.