The company will continue to work with its existing agencies, AKQA and glue, but is looking to add more large-scale agencies to cope with its expanding volume of work.
WCRS's sister agency Meme, which has worked on projects for Sky Networks, is not being considered because of its size.
Last year, Sky spent £20 million on online display advertising and intends to increase this by 15 to 20 per cent this year. It is also looking for search agencies to handle its pay-per-click and natural search opportunities.
The latest hunt comes seven months after Sky launched an agency review through the AAR. It was, however, called off before the pitches began.