Sienna Miller is planning to launch her own fashion label.

According to Grazia magazine, Miller will work on the label with her designer sister Savannah. Savannah graduated from the same fashion college as Stella McCartney and Matthew Williamson.

A source told the magazine, "Sienna has great fashion sense but Savannah is the one with the real design talent. She was a star pupil at college and the label's bound to be successful.

The pair has a financial backer in place and hope to launch the collection in spring 2007. The sisters are working together to make sure that everything is perfect because of Sienna's high media profile.

The insider added: "Savannah knows the label will be hyped because of her sister's fame and that many people will be quick to criticise."