Brands Hatch, Cadwell Park, Oulton Park and Snetterton were sold by parent company Interpublic Group (IPG) to MotorSport Vision for an undisclosed sum.
IPG retained the 15-year lease to operate the British Grand Prix at Silverstone.
Andrew Waller will remain at Silverstone Motorsport as managing director.
Marketing communications manager Alasdair Farrimond will be replaced by former MG Rover UK marketing manager Alex Watkins at the end of March.
MotorSport Vision is run by former racing driver Jonathan Palmer, who also owns Bedford Autodrome.