LONDON - A piece of royal history will soon be auctioned in the form of a sexy see-through dress that Kate Middleton modeled at a fashion show in the early days of her relationship with Prince William.

Middleton wore black lingerie under the transparent dress in a 2002 charity fashion show William attended during their undergraduate days at St. Andrew's University in Scotland. It is thought he was intrigued by the revealing garment.

It will be sold at Kerry Taylor Auctions in London on March 17. Officials expect it to fetch more than 8,000 pounds (US$12,800).

Designer Charlotte Todd initially said she would not sell the unique outfit but has changed her mind. She did not go into fashion full time and is working at an aquarium.