The party is on the lookout for a successor to Young, both as chief spokesman for the party leader -- Young led William Hague's campaign bus press team in June's general election -- and as head of the shadow chancellor's press operation.
A spokeswoman said the party would replace Young, but added that no decision had been taken on whether to fill his dual roles with one or two hires.
Young was released early on in his notice period at Smith Square to take up the Granada job. He started this week, and reports to corporate affairs director Susan Donovan.
Overseeing eight staff in communications, Young replaces Tim Hollingsworth, who left the company earlier this year to join PR firm HBL Media (PRWeek, 25 May).
Young will head external and internal comms, which were split when Hollingsworth left. Former Reuters PRO Philip Candice, who has now left the company, headed the internal communications division.
Granada has gone through a period of turbulence in recent years, disposing of its hospitality interests -- hotels and the rebranded Moto motorway service station chain -- and adding to its TV concerns.
The firm now owns half the ITV network through six franchises - LWT, Anglia, Meridian, Yorkshire, Tyne Tees and Granada itself. It also has a half share in ITVDigital and turned over £4bn in 2000.
Young's PR background goes back just three years. After more than a decade as a banker at Barclays, he became the company's euro communications manager ahead of the single European currency launch in January 1999.
He then served for a year and a half as deputy head of corporate PR under director Chris Tucker before moving to work for the then shadow chancellor Francis Maude.