SHE's one of the only women on Earth who actually looks good in skinny jeans.

Now Sienna Miller is taking her love affair with denim even further by designing her own exclusive range.

The actress, famed for her boho chic, has signed a multi-million-pound deal with trendy label Pepe to produce a unique line.

If everything goes to plan, the jeans should be unveiled next season.

Sienna, 24, whose romance with Jude Law has been on and off more times than Prezza's trousers, is following in the footsteps of Victoria Beckham, whose range of jeans for Rock and Republic proved to be a best seller.

A fashion insider tells us: "Sienna has become a style icon in such a short space of time.

"She's been on the cover of Vogue, everyone knows who she is and this is the perfect time to do something like this. The jeans will be her own unique designs and the fact that she can model the clothes herself makes the whole project even more exciting.

"Even though she is ultra-skinny, her jeans will be made to flatter most sizes. The hope is she'll do for Pepe what Victoria Beckham has done for Rock and Republic."

This weekend Sienna who, as well as seeing Jude, has been stepping out with DKNY model Nico Malleville, is co-hosting a star-studded party with American Vogue editor Anna Wintour and Burberry designer Christopher Bailey to celebrate a new exhibition at New York's Metropolitan Museum of Art.

The AngloMania bash is a celebration of London fashion over the past 30 years and will feature designs from the likes of Malcolm McLaren and Vivienne Westwood. Says our nsider: "It's the hottest ticket in town and it will really help establish Sienna."

The starlet, who's been filming Interview with Steve Buscemi, began working with Pepe Jeans after signing an exclusive deal to be the "face and body" of the brand in November.

Her contract apparently included a clause preventing her wearing anyone else's jeans - but she was pictured in a magazine wearing a pair of rival LoFLi's.

Pepe insisted the photograph was an old one. Let's hope so...