IBM CEO Gini Rommetty, 31, has been ranked America's most powerful businesswoman of 2012 by Fortune magazine.

Rommetty has played a key supporting role in some of the company's biggest developments, such as acquiring PwC Consulting for $3.5 bn and extending IBM to the service business.

Chairman and CEO of Pespsi Co, Indira Nooyi, has maintained her second rank from the previous year while Hewlett Packard CEO Meg Whitman rises to the third position.

Pepsi Co had seen a rise in its profits and revenue for 2011. Nooyi is keen on pushing the company to focus more on "good for you" products, although investors fear that such an action could damage PepsiCo's core business.

HP, which was expected to see improvement under Whitman is still underperforming, reporting a 19 percent fall in profits. But with $127 bn annual sales, the company gives Whitman enormous power even as speculations of her ability to restore the tech giant back to the growth path swirl, said Fortune.

Kraft Foods Chairman and CEO Irene Rosenfeld has slipped from her first spot in 2011 to the fourth place this year.

Rosenfeld is considered to be the think-tank behind Kraft Food's upcoming division. She will head Mondelez International and be responsible for its $54 bn revenue while holding on to brands like Oreo, Tang and Ritz.

Dupont chair of the board and CEO Ellen Kullman, instrumental in the restructuring of the 210-year-old company has been named the fifth most powerful businesswoman in the world. Earlier this year she had sold Dupont's auto paints section for $4.9 bn.

Patricia Sellers, Fortune magazine's editor at large said that the concept of power has changed in the minds of the most powerful women over the years.

She added the spotlight this year was on two women, Gini Rommetty at the top spot and Yahoo CEO Marissa Mayer at No 14, who is the youngest member to make it to the list and the youngest CEO of a Fortune 500 company.