NEW YORK: US first lady Michelle Obama beat out heads of state, chief executives and celebrities to rank as the world's most powerful woman in Forbes magazine's annual listing. Kraft Foods Chief Executive Irene Rosenfeld, who led a hostile $18b takeover of Britain's Cadbury, came in second, followed by talk show host and media mogul Oprah Winfrey, who is ending “The Oprah Winfrey Show” next year after 25 years to launch her cable network OWN. German Chancellor Angela Merkel, elected for a second term last year, was the fourth most powerful woman, while US Secretary of State Hillary Clinton, who was put in charge of brokering Middle East peace, rounded out the top five. Moira Forbes, vice president and publisher of ForbesWoman, said the women on the business magazine's list were “shaping many of the agenda-setting conversations of the day.” “They have built companies and brands, sometimes by non-traditional means and they have broken through gender barriers in areas of commerce, politics, sports and media and cultural zeitgeist, and thereby affecting the lives of millions, sometimes billions of people,” she said. This year Forbes changed the way it ranked women, basing the list less on wealth and power and more on creative influence and entrepreneurship. Last year's winner was Merkel, followed by Sheila Bair, chairman of the Federal Deposit Insurance Corp. Obama ranked No. 40. Forbes said Obama topped the list this year because “she has made the office of first lady her own” while remaining popular. The complete Forbes list of the 100 most powerful women can be seen at www.forbes.com/powerwomen.