Billionaire heiresses to watch

Just a year ago, Holly Branson seemed poised to follow a very different career path from her father, British billionaire Richard Branson, who built his Virgin empire from scratch. Indeed, the flamboyant entrepreneur's only daughter had spent five years studying at London's University College preparing to become a pediatrician.

Yet last summer the allure of her family's business proved too great to pass up. Soon after completing her studies, Holly decided to forgo her medical career and join Virgin instead. The British scion who is said to be pals with Prince William, is now spending a year working in Virgin's various groups and has already spent time in its health, fitness and airline businesses.

Holly is hardly the first heiress to abandon her own plans to join the family business.

Alannah Weston, daughter of Canadian retail billionaire Galen Weston who spent years writing about contemporary art for the Daily Telegraph and working as a public relations executive for Burberry, eventually started her own corporate branding business in 2003.

But that same year her father convinced her to become creative director of Selfridges, a luxury department store chain in the UK he had just bought. "I was reluctant to fold up (my business), having just started it," said Alannah, 37. "But my family convinced me that this was the perfect job for me."

These women are the latest in a long line of billionaire offspring who have decided to work for mom or dad. The allure seems obvious: lots of responsibility at a young age, little chance of being fired by the boss and the opportunity to contribute to the family's legacy.

But how seriously do these women take these jobs, and how likely is it that they'll actually inherit the corner offices, eventually run billion-dollar enterprises and oversee thousands of employees?

To find the most promising progeny, we scoured the daughters of the world's 793 billionaires and found 25 worth watching. They range in age from 25 to 59, include a couple sets of sisters and hail from 12 countries and work in such diverse industries as cosmetics, media and shipping.

Not included are any heiresses who have already inherited the fortune as well as the business, thus eliminating someone like Margaret (Maggie) Magerko, 43, who now runs and owns 84 Lumber, founded by her father. Also left off are ones who are succeeding on their own, such as Ralph Lauren's daughter Dylan, who owns the popular Manhattan store Dylan's Candy Bar.

So who are the rising stars? One of the best known is Donald Trump's daughter Ivanka, who seems destined for the job. At 27, she has already become a fixture in her father's empire as an executive vice president for the Trump Organisation and a star in her dad's primetime show Celebrity Apprentice. Enterprising as the Donald himself, Ivanka has also found time to be a fashion model and the face of Ivanka Trump Jewelry, her own luxury diamond line.

Others already sit on the boards of the world's largest public companies. Vanisha Mittal Bhatia, 28, is a board member of steel behemoth ArcelorMittal (market cap $37 billion), along with its chief executive, her father Lakshmi Mittal, and American billionaire Wilbur Ross. She is the only family member besides her dad on the board, though her brother Aditya Mittal is CFO and member of the Group Management Board.

Meanwhile, France's Delphine Arnault-Gancia, 34, became the first woman board member of luxury goods group LVMH Moët Hennessy Louis Vuitton, run by her father, at age 28 and was named deputy managing director of Christian Dior in April 2008.

The two most powerful heiresses already run significant businesses. Marina Berlusconi, daughter of three-time Italian Prime Minister Silvio Berlusconi, left her studies at the University of Milan before obtaining her degree in order to work at Fininvest Group, the holding company established by her father. She now chairs the group, which includes interests in a major commercial TV operator, a movie production company and soccer team A.C. Milan. It was enough to help her rank 34 on our list of the world's most powerful women.

Seventeen spots below her was Ana Patricia Botin, at No. 51. She is considered her father Emilio Botin's heir apparent at Spanish bank Santander, founded by her great-great grandfather. This Harvard-educated economist began her career at JPMorgan Chase and then joined the family business in 1988, playing an active role in the bank's expansion into Latin America. She has headed Banesto, the retail subsidiary, since 2002, earning a reputation as a savvy banker but now comes her biggest test as she tries to manage the bank amid global economic turmoil.

It may be years for other heiresses to climb as high as these two leading ladies, but one thing is certain: These women all have grander ambitions than simply living a pampered life and spending their parent's money.