W.I.T.C.H. tells the story of five female friends - the letters correspond to their initials - and is aimed at nine- to 12-year-old girls.
A magazine launches in the UK on 6 April, while an animated TV series will kick off on the Jetix channel (formerly Fox Kids) three days later.
Books and various other merchandise will also go on sale.
Braben, which has formerly worked on other projects with both Jetix and BBC Magazines - the publisher of W.I.T.C.H. magazine - won the contract after a competitive pitch.
W.I.T.C.H. magazine was established in Italy in 2001.