AOL has announced the purchase of Adtech AG, an online ad company based in Germany.

The news come just a day after AOL purchased mobile advertising company Third Screen Media – both companies will operate within AOL’s Advertising.com business.

This is a further extension of AOL’s recent strategy, with the company moving away from its roots as an ISP to building up its interests in online advertising.

The acquisition of Adtech provides the company with an ad serving platform which serves web publishers in 25 countries and allows them to  manage and report on their online ad campaigns.

While AdTech is primarily based in Europe, it recently began operating in the US  where it competes directly with DoubleClick, which was recently acquired by Google for $3.1bn.

The financial terms of the AOL/Adtech deal were not disclosed.