Blackmore, who founded the Unique Broadcasting Company with chief executive Simon Cole in 1989, will continue to serve as chairman of Classic Gold Digital and Oneword Radio.
He will also continue to be a consultant editorial director for UBC Media. The decision to scale back Blackmore's workload comes as the 59-year-old approaches retirement.
But Blackmore said he anticipated 'playing a continued role in the development of the company in the years ahead.'
Blackmore, who has been a pioneer for digital radio, began his career with the launch of BBC Radio 1 in 1967. After producing Tony Blackburn's show he created the Sunday morning Noel Edmonds show, before moving to Capital Radio when it overtook the BBC for the first time.
He served as the first director of the Radio Academy and was awarded an MBE for services to independent radio production in 1999. Blackmore has also been awarded a fellowship of the Radio Academy and is chairman of the Sony Radio Academy Awards.