The deal is financed by mid-market private equity house Exponent, which bought Gorkana through Durrants. Durrants also acquired media evaluation specialist Metrica in October 2009.
Gorkana's founders Alex Northcott and Michael Webster, who launched the business in 2003, are to remain at the firm. Reports suggest that all the firm's equity will be bought by Exponent, with Northcott and Webster retaining small stakes.
In an email to clients, Northcott said: ‘This acquisition brings together three market leaders, all with strong reputations for delivering exceptional services and customer support.
‘Over the coming months we will be looking at how Gorkana and Durrants will integrate to the benefit of clients and we will communicate this as decisions are made.'
The acquisition will give Durrants and Metrica access to Gorkana's specialist online products, while Gorkana hopes to use the deal to expand internationally and grow its product range.