Microsoft has agreed to purchase digital marketing company aQuantive in a deal worth $6 billion. AQuantive is the parent company of digital marketing services provider Atlas, online ad space buyer DrivePM and interactive agency Avenue A | Razorfish, whose client roster includes healthcare companies AstraZeneca, Wyeth and Boston Scientific. “We’re very excited about the Microsoft deal and the impact it will have on our business,” Avenue A | Razorfish EVP, product development Brad Aronson told MM&M via e-mail, shortly after the deal was announced. “Of course, we’re as committed as ever to our current clients and look forward to the additional resources we’ll be able to leverage on their behalf.” The aQuantive deal marks Microsoft’s biggest-ever acquisition as the firm strives to catch up to Google in the online ad market. Last month, Google agreed to purchase aQuantive rival DoubleClick for $3.1 billion. The deal also marks the fourth major Web ad acquisition since April 13, when Google announced the DoubleClick deal. WPP Group agreed to buy digital marketing agency 24/7 Real Media. And last month, Yahoo! agreed to buy the 80% of online media firm Right Media it doesn’t already own.