Microsoft has bought online advertising firm aQuantive for about $6bn (£3bn), giving it ownership of ad technology provider Atlas; interactive agency AvenueA/Razorfish; and Drive PM, which provides targeting tools for internet advertisers and publishers.

The announcement of the deal follows a wave of consolidation seen in the online ad market recently –Google’s DoubleClick deal, AOL’s acquisition of AdTech and WPP’s purchase of 24/7 Real Media.

The purchase of Atlas is an especially significant move - it competes against DoubleClick’s technology platform, allowing advertisers to place ads more efficiently and publishers to better manage their inventory.

According to Microsoft:

“This deal expands upon the company’s previously outlined vision to provide the advertising industry with a world class, Internet-wide advertising platform, as well as a set of tools and services that help its constituents generate the highest possible return on their advertising investments.”