The news comes as BSkyB unveils an interim profit surge of 25 per cent and 192,000 new customers.
W&K will create a series of campaigns for Sky One's flagship shows, which include the real-time drama series 24, Nip/Tuck and The Simpsons.
HHCL/Red Cell, the incumbent on the BSkyB account, was not involved in the pitch process. However, it will continue to handle the rest of the Sky business, including advertising Sky as a platform and promoting the Sky Plus set-top box.
Sky One faces tough competition in the multichannel market. In January, ITV2 overtook Sky One as the sixth-most-watched channel in the UK. In the seven days to 23 January, ITV2 achieved an average 2.3 per cent share.
BSkyB is repositioning Sky One, taking less account of audience figures alone and placing more emphasis on customer satisfaction. This is designed to contribute to BSkyB's primary focus of driving new subscribers.