Rometty, 55, will become the first female chairman of IBM, of Armonk, N.Y., in its 101-year history, when Palmisano, 61, retires as chairman and director to become a “senior adviser” to the company. IBM is the No. 2 computer maker.
The promotion will make Rometty perhaps the top-ranked woman in U.S. technology. At the biggest computer maker, Hewlett-Packard Co. (NYSE: HPQ), CEO Margaret (Meg) Whitman, 56, reports to Chairman Ray Lane, 65.
At Yahoo Inc. (Nasdaq: YHOO), in Sunnyvale, Calif., new CEO Marissa Mayer, 38, reports to Chairman Fred Amoroso, 62, a onetime IBM senior manager.
IBM has two other women on its board: Joan Spero, 67, a former executive VP of American Express Co. (NYSE: AXP), and Shirley Ann Jackson, 65, a physicist and president of Renssalaer Polytechnic Institute.
This will be the second time Rometty succeeds Palmisano, because she inherited his job as CEO. At the time, it was believed the board passed over another top IBM executive, Linda Sanford, 59, now senior VP for enterprise transformation, because she couldn't serve very long in the post.
By custom, IBM CEOs retire around age 60. Palmisano did, as did his predecessor, Louis V. Gerstner Jr., who was brought in from RJR Nabsico (NYSE: RAI) in 1993 after IBM nearly went broke.
Although women hold ranks such as chief operating officer at Facebook (Nasdaq: FB), the No. 1 social networking site, co-president at Oracle Corp. (Nasdaq: ORCL), the No. 1 database developer, and senior VP at Texas Instruments Inc. (Nasdaq: TXN), few have been chairman or even CEO.
Carol Bartz, 65, was CEO of Yahoo until last year and had served in the same role at Autodesk (Nasdaq: ADSK) before becoming chairman of that design software company. Her firing last September led to an outcry by women's groups about lack of representation in the boardroom.
Women are presidents of several top Ivy League colleges, including Princeton, Harvard, Brown, University of Pennsylvania and Dartmouth; Princeton's Shirley Tilghman is a molecular biologist while Dartmouth's interim president, Carol Folt, is a biologist. The other women are all social scientists.
Separately, the Institute of Electrical and Electronic Engineers reports that the overwhelming majority, 89.7 percent, of its members are male, while only about 10 percent of current graduates are female. The IEEE and other education groups have campaigns to promote women in technical professions.
IBM shares rose $2.61 to $206.59 in late Thursday trading.