Media Square has sold Karen Earl Sponsorship, the London-based sports sponsorship consultancy, to The Engine Group for £3.5m. KES provides strategic consultancy through to sponsorship activation and only works for sponsors, not for rights owners. The agency, named Marketing magazine Sponsorship Agency of the Year in 2005, has clients including Aviva, British Airways, Coca-Cola, Guinness and RBS. The deal is the third investment made by The Engine Group this year. Peter Scott, chief executive of Engine, said: "KES is an ideal business to be working alongside the Engine Group's partner companies. This will create tremendous synergies with several of our businesses in digital, public affairs, events and direct marketing." Karen Earl, founder of KES, said: "As part of the Engine Group, we will be ideally placed to take advantage of sponsorship's appeal to an increasing number of clients."