Olsens' new clothing range

Mary-Kate and Ashley Olsen are set to launch a new clothing line.The 20-year-old twins - who have already created an exclusive collection for US supermarket chain Wal-Mart and have their own high-end couture label The Row - will add Elizabeth and James, a contemporary sportswear range, to their fashion portfolio this autumn.The new brand, created in partnership with L'Koral Industries, was named after the twins' other siblings.Mary-Kate told Women's Wear Daily magazine said: "We wanted it to be based on a relationship between a girl and a boy and tell the story through clothing.Ashley added: "It's a clash between masculinity and femininity."Elizabeth and James - which will go on limited sale - features blazers, washed leather jackets, military-inspired tops, shrunken T-shirts, cashmere coasts and sequin mini-dresses.Ashley said the wearer they had in mind was a "sophisticated woman with a playful side and is still chic. It's someone who understands fashion and understands details and expects that as well."

The style-icon siblings, who rose to fame in ABC sitcom 'Full House', topped this year's Young Hollywood's Top-Earning Stars list, compiled by Forbes.com.

Mary-Kate and Ashley pocketed $40 million last year from their retail empire, making them the richest under-21s in showbiz.

The young business moguls are reportedly worth around £300 million thanks to their "tween" merchandise, clothing line and movies.