Hollywood actresses Sienna Miller and Keira Knightley share an appetite for success, but not, it appears, fatty food.

The costars cut very lean figures as they hit the red carpet at the world premiere of Edge of Love which opened the Edinburgh Film Festival.

Sienna sashayed along in a black tasselled dress by Jasmine de Milo topped with a rather bizarre vintage bowler hat, while Keira wore a cream Chanel Jumpsuit and black Chanel cardigan.

Lean girls: Sienna Miller and Keira Knightley at last night's premiere of Edge of Love in Edinburgh

They were joined by a host of other stars, including Sean Connery, with his arm in a sling, and Joely Richardson, who looked glamorous in a metallic confection.

Unlike the hordes of screaming fans expected at venues such as London's Leicester Square, the premiere was a low-key affair with no more than 200 fans in attendance.

As well as being adversaries in the glamour stakes, the pair play love rivals in the biopic of Welsh poet Dylan Thomas, played by Matthew Rhys.

Love triangle: Sienna with co-star and ex-boyfriend Matthew Rhys, and Keira Knightly. Her closeness to the actor allegedly caused problems between Sienna and Rhys before they split

Tangled up: Sienna and Keira laugh off a wardrobe mishap

Glamour: Joely Richardson dazzled on the red carpet in a metallic confection

Last night Miss Miller, 26, dismissed any rivalry with her co-star and said: 'She is one of my favourite girls'.

Mr Rhys posed with them amid reports that it was the closeness between him and Miss Miller which  recently broke off her romance with Notting Hill actor Rhys Ifans.

Miss Miller is cast as Caitlin MacNamara, Thomas's wife, while Miss Knightley took on the role of Vera Philips - the childhood sweetheart who returned to fight for her former lover's affections.

The film also stars Irish actor Cillian Murphy who plays Knightley's devoted husband William Killick.

The screenplay was written by Miss Knightley's mother Sharman Macdonald and it was her daughter who persuaded director John Maybury to take it on.

Miss Macdonald had originally written the part of Caitlin for her daughter while on location in the Bahamas while she filmed Pirates of the Caribbean.

It was certainly Miss Knightley's star power which dominated the press conference and premiere yesterday putting her co-star, who is three years her elder, in the shade.

Miss Knightley is a firm Hollywood favourite with an Oscar nomination for her performance in Pride and Prejudice and a fanbase from the Pirates of the Caribbean trilogy which first hit screens in 2003.

The current face of Chanel, her £3million contract will end this summer and she has an estimated fortune of £18million.

Meanwhile Miss Miller has long been dubbed 'one to watch' without yet having a box office hit.

She first found fame as Jude Law's fiancee whom she met on the set of Alfie, a film in which she had a small part.

She continued to generate headlines as the poster child of boho chic and then as the betrayed fiancee after it was revealed that Law had an affair with his children's nanny in 2006.

The Edge of Love is her highest profile role to date though she announced yesterday she will star alongside Russell Crowe as Maid Marian in a remake of Robin Hood.

Still smiling: Sean Connery managed a grin despite his injured arm, accompanied by his wife, Micheline Roquebrune-Connery