
Sykes held the role of managing director, content strategy at HomeChoice, the IPTV service that is the basis of Tiscali TV.
HomeChoice was acquired by Tiscali in 2006 for an undisclosed sum. Tiscali was subsequently bought by The Carphone Warehouse in May for £236m.
It is understood Sykes left without a job to go. Prior to joining HomeChoice, he was chief executive of cable group NTL's subsidiary Premium TV (now known as Perform). Before that, he spent nine years at BSkyB in various roles, including that of general manager of Sky Sports.
The Carphone Warehouse said: "Jonathan Sykes has left the business and we thank him for his contribution and wish him every success in the future. TalkTalk will ensure customers who subscribe to Tiscali TV continue to receive a first-class service."