Octopus will also inject a further£2m to expand BDA. The company will use the funds to open divisions in China, Mumbai, Johannesburg and Moscow over the coming months.
The company is particularly interested in China and India, where there is rapid channel growth, with analysts predicting an increase in the number of Indian TV channels of 50% to 70% over the next two years.
BDA already has offices in London, Munich, Dubai, Singapore, Sydney and Beijing and is currently working on the official opening title sequence for the 2008 Olympic Games.
Octopus was one of nine trade and private equity firms to show interest, which BDA group managing director Honor Barratt said pointed to the appetite investors have for the media sector.
She said the company plans to service large international clients and is in negotiations with two unnamed UK broadcasters regarding long-term contracts.
The next stage of its growth will involve strategic acquisitions and investments in the digital and non-broadcast side of the business. A first deal is understood to be imminent.
BDA is headed by Barratt and group chairman and creative director Bruce Dunlop who was creative director of BSkyB between 1992 and 1998.
Dunlop was responsible for launching Sky's multi channels and led the strategy and design that created a cohesive look to the channel group.
BDA competes with companies such as Red Bee Media which is also developing an international presence.