Twin Teen Moguls to Launch $1B Hollywood Empire

The girls, who act, dance and sing, are already worth an estimated $100 million. Analysts believe a flotation of their Dualstar Entertainment Corp, perhaps next year, could make them more than 10 times as rich.

They will control interests in television and film production, music, fashion, book publishing, toys and the internet that rival some of Tinseltown's biggest conglomerates.

Olsen merchandise is expected to arrive in Britain early next year, aimed at the booming market among pre-teen girls.

In America the Olsens' top-rated television films such as Double, Double Toil and Trouble have been hugely successful. Their first album, I am the Cute One, sold 325,000 copies and they have more than 100 books in print. New editions come off the presses at the rate of two a month.

The Olsens have produced 30 musical detective videos, which have earned more than $400m and made the Dualstar Video label second only to Disney in the children's market. A recent video, Passport to Paris, has been the number one children's video in America since Christmas. The girls' internet site receives 270m hits a year.

Mary-Kate and Ashley may be unknown in Britain, but they have been stars in America since they were babies. They were nine months old when they first appeared on the television sitcom series Full House, which at its peak had an audience of 55m people a week.

The series lasted for nine years and the bug-eyed twins grew up in front of America, alternating in the role of Michelle Tanner, the show's young child. By the time Full House ended in 1995, they were being paid $80,000 an episode. Royalties continue to flow in from 56 countries where the show is still broadcast.

Skillfully managed from the outset by Robert Thorne, an entertainment lawyer, the Olsens went on to star in Two of a Kind, a television series which helped to cement their appeal to their loyal young female following. Hollywood's so-called "Q" ratings, which measure the popularity of stars, show that the Olsens are the most popular and recognisable young Hollywood icons among Americans aged between 6 and 11.

Born on June 13, 1986, the Olsens are not identical twins but are said to be "so close that they share the same face". Ashley, who is right-handed and more talkative, was born two minutes before Mary-Kate, who is left-handed and a keen showjumper.

They live in Los Angeles with Trent, their older brother, and Elizabeth, their younger sister. Their parents are divorced but share custody of the girls. According to sources close to the family, they have not plundered their fortune like the parents of some child stars.

The twins have been "executive producers" on all their films, videos and television programmes since they were seven. As they move into adolescence they have become increasingly involved in making decisions about their careers and their expanding empire.

They meet Thorne once a week and determine the casting of their shows, pick photographs for their CD covers and choose clothes for their fashion line, sold through Wal-Mart.

"They're just regular people," said Thorne. "Of course, they're extremely wealthy and they're used to a limousine when they're working, but they don't care about the limousine and they don't care about the money."