ITV snapped up the independent production company behind such hit TV series as Inside Claridge's and 24 Hours in A&E yesterday.
It is paying an upfront £18m in cash for The Garden, the company that was founded three years ago by Nick Curwin and Magnus Temple.
It is the second time the duo have sold an independent production house, having sold their first company Firefly to Elisabeth Murdoch's Shine for a reputed £10m in 2007.
ITV said it could pay further cash for The Garden "on the delivery of significant profit growth over the next five years". The company had an operating profit of £2.5m in 2012.
Kevin Lygo, the managing director of ITV Studios, said: "The Garden has grown rapidly and achieved an enviable reputation for outstanding delivery of innovative, ambitious documentary series for the BBC and Channel 4.
"A key focus for ITV is to develop hit programmes which we can then export. The Garden already has an impressive track record. Its flagship title – 24 Hours in A&E – is not only a hit for Channel 4, but has sold to nearly 100 territories around the world."