Sky has shortlisted agencies using matchmaker AAR ahead of pitches taking place in the New Year. The UK brief covers a range of products and services including products and services such as Sky+, HD, Sky Go, 3D and internet-delivered spin-off NOW TV.
Cake declined to repitch, with a spokeswoman citing "creative differences", and is understood to have finished work on the account today.
A Sky spokeswoman said: "As Sky moves into a new phase of growth, it feels like a natural point for us to take a fresh look at our brief, and also our needs and requirements from a retained PR agency.
"We’d like to thank Cake for their creativity, support and hard work over the past six years and wish them all the best for the future. They have set a high bar for any incoming agency to meet with the quality of the creative campaigns they have delivered for us."
The British arm of Sky, officially called BSkyB, reported an eight per cent drop in profits to £285 million in the three months to the end of September.
It has more than 10 million customers and its TV and broadband subscriptions have been growing, but it is facing the strongest competition for sports rights in years from BT, which recently acquired the rights to show live games from premier European club football competition the Champions League.
Sky’s relationships with other agencies, including Freuds’ work on content and CSR and Finsbury’s financial PR brief, are unaffected.
However, Freuds has the opportunity to pitch for the brief alongside other shortlisted agencies.
A spokeswoman for Cake said: "We [Cake and Sky] are going in different directions, and we’re pushing for a more integrated approach which is more focused on social. You could call it creative differences."