Sienna and Savannah Miller have stepped down as the co-creative directors of fashion label Twenty8Twelve.

The siblings - who have worked with the brand since it formed in 2007 - have decided to pursue other ventures although the British label will continue under its current design team.

They said: "We've had a brilliant six years at Twenty8Twelve and are now looking forward to new pastures. We wish the brand the best of luck for the future."

Nish Soneji, managing director of Twenty8Twelve, said: "We've had a great partnership with the Miller sisters. From the beginning, our mission was to create a contemporary label with its own identity and strong directional design, as well as an emphasis on quality, cut and finishing. That vision, along with the uniquely British style the collection has become known for, will continue under the direction of the Twenty8Twelve design team."

Twenty8Twelve was named after Sienna's birth date of 28 December while her older sister Savannah has a first class degree in fashion design with knitwear from Central Saint Martin's and has worked for Alexander McQueen, Anya Hindmarch, Betty Jackson and Matthew Williamson.

Nish added that starting with the autumn line, the label will read, Twenty8Twelve London, rather than Twenty8Twelve by s. miller.

The label has three stores in London with Mr. Soneji adding: "I've been struggling the last five years to find a location in New York."