Jill Barad, who made Barbie into a selling sensation and helped build Mattel into a corporate powerhouse, has stepped down from the helm of the world’s biggest toymaker after failing to revive falling sales and profits.

Barad, 48, one of the highest ranking women in business, was under intense pressure from investors and Mattel’s board of directors to explain big losses at the company’s newly acquired Learning Company software division and other troubles at Mattel.

Barad resigned Feb. 3 as the El Segundo, Calif.-based company reported a steep loss for the fourth quarter, disappointing Wall Street analysts for the third time in the past four quarters.

Mattel’s acquisition of The Learning Company was a big factor in the loss. The software division lost $183 million in the quarter and $206 million for the year.

Barad joined Mattel in 1981 as a product manager in the novelty toy unit and became CEO in 1997. Her flashy style and aggressive marketing savvy lifted her to the top.

Under her supervision, Barbie was transformed from a tired, $200 million product line into one of the most recognized brands of all time with $1.9 billion in sales last year.

She also was able to recognize the changing desires of techno-literate kids today, who learn to use a computer in preschool. Mattel has stepped up its software and online offerings, and looked to new avenues to capture shoppers.

But the company’s acquisition of The Learning Company, seen by many investors as a smart move in light of the growing importance of educational software to the future of the toy market, so far has not worked out as planned.

When the acquisition was announced in February 1999, The Learning Company was considered the world’s second-largest consumer software company after Microsoft, with about $850 million in projected revenue in 1998. The company produces such software titles as Reader Rabbit and Carmen Sandiego.

Barad was considered a pioneer of women in corporate America. She was only one of four women CEOs heading Fortune 500 companies. The others are Andrea Jung of Avon, Carleton S. Fiorina of Hewlett-Packard, and Marion D. Sandler of Golden West Financial.

With her resignation, the board of directors will take charge of the company to oversee operations and search for a new chief executive officer. The board appointed two of its own members to leadership roles, picking William Rollnick as acting chairman and Ronald Loeb as acting CEO.