ITV had expected to name Hytner's successor a month ago from a shortlist of three, which included Salmon. However, it is believed she accepted the role only after it was broadened to include a remit for programming and digital channel development.
Hytner's role had been diluted after Justin Sampson, the former Radio Advertising Bureau managing director, joined ITV in January in the new post of director of customer relationship management. This effectively took away Hytner's responsibility for marketing to advertisers, and he quit in June to become the top marketer at Barclays.
Salmon, who takes up her role in mid-January, will report to ITV Broadcasting chief executive Mick Desmond. She will be responsible for both on- and off-air marketing for ITV1, ITV2 and ITV3, and will also create an audience research function.