Sizmek was declared bankrupt in March this year and the financial details of this deal have not been disclosed.

In a statement, Amazon said: "Sizmek and Amazon Advertising have many mutual customers, so we know how valued these proven solutions are to their customer base. Sizmek has been searching for a buyer for Sizmek ad server and Sizmek DCO, and we are both committed to continuing serving their customers at the high standards they’ve come to expect."

Once the deal is completed, Sizmek ad server and DCO will operate separately from Amazon Advertising initially.

It will give Amazon a significant ad server capability, with associated online consumer data, and demonstrates Amazon’s advertising ambitions and desire to challenge Google and Facebook, the two largest online advertising businesses.

Its ad revenue is currently small compared with its online retail business but it is growing – up 34% to $2.7bn in its most recent quarter.