IBM's new CEO Virginia Rometty. Courtesy IBM

It’s been a hundred years and zero women have held the top position at IBM but all that will change when Virginia “Ginny” Rometty takes the reins as CEO of the technology company.

Rometty will join a list that includes Meg Whitman, the former eBay CEO,  who was named as CEO of  Hewlett-Packard in September. The moves will make two women the head of two of the top tech companies.

“Ginni’s long-term strategic thinking and client focus are seen in our growth initiatives, from cloud computing and analytics to the commercialization of Watson. She brings to the role of CEO a unique combination of vision, client focus, unrelenting drive, and passion for IBMers and the company’s future. I know the board agrees with me that Ginni is the ideal CEO to lead IBM into its second century,” outgoing CEO Sam Palmisano said in a statement.

The 54-year-old  strategic thinker will begin her role at the top on Jan. 1. And, on the same day next year,  over at Mylan Inc., Heather Bresch will take on her new role of CEO at the pharmaceutical company. The three  appointments in the last few weeks will help boost the amount of women CEOs to record numbers.

According to USA Today, only 16 women have headed up Fortune 500 companies at the same time. But, pending no shakeups before the New Year, the total number of women leading Fortune 500 companies will rise to 18.

The number is a demonstrates progress, says Lucy P. Marcus, CEO of Marcus Venture Consulting.

“Over time, we’ll see more women being chosen to lead Fortune 500 companies.  It is inevitable – there are many accomplished women who have risen through the corporate ranks and they will make excellent CEOs and board members,”  Marcus said in a statement to ABC News.

According to USA Today, in 2011, “there were 98 female CEOs of 3,049 publicly traded companies analyzed by research company GMI.”  The total number of women represents 3.2% of the total company CEOs, an increase of .1 percent from last year.

Marcus says  more companies can bring women into the fold by providing committed mentorship programs and by developing the skills needed for success:   international exposure, strong skill building and role models.

“There has been progress in bring diversity to the board room, but there is no doubt that women are severely under-represented,” wrote Marcus. “I think we will see progress accelerate now that the conversation about bringing diversity to the board room has become a mainstream discussion.”

“What is important to is to remember why diversity in the boardroom is important: the lack of women on boards, is a reflection of a wider problem with diversity: it is one of color, age, international perspective, and more. Board rooms that don’t represent the stakeholders of the business and the environment in which companies are operating are not able to do their jobs as capably,” she continued.

 Here’s a Look at The 18  Women CEOs of Fortune 500 Companies:

1. Gracia C. Martore of Gannett Co.
2. Denise M. Morrison of Campbell Soup
3. Deanna Mulligan of Guardian Life Insurance Company of America
4. Debra Reed of Sempra Energy
5. Beth Mooney of KeyCorp
6. Lynn Elsenhans of Sunoco
7. Ursula Burns of Xerox
8. Ellen Kullman of DuPont
9. Laura Sen of BJ’s Wholesale Club
10. Angela Braly of WellPoint
11. Carol Meyrowitz of The TJX Companies
12. Indra Nooyi of PepsiCo
13. Irene Rosenfeld of Kraft Foods
14. Patricia A. Woertz of Archer Daniels Midland Co.
15. Andrea Jung of Avon Products
16. Margaret “Meg” Whitman of Hewlett-Packard
17. Virginia “Ginni” Rometty of IBM Corp
18. Heather Bresch of Mylan Inc.