Microsoft has incurred a $6.2 billion write-down after a online advertising technology provider it acquired in 2007 failed to grow as fast as expected.

The goodwill impairment, worth almost as much as the $6.3 billion Microsoft paid for aQuantive, may cause the software giant to suffer its first quarterly loss in more than a decade. Analysts had previously expected the company to report a $5.3 billion.

AQuantive sells software that allows advertisers and publishers to plan and manage their online advertising portfolios. At the time of the acquisition, Microsoft said it "is an important step toward our goal of becoming an industry leading, Internet-wide advertising platform”.

The company said yesterday that it has downgraded its expectations for its Online Services Division, which includes search engine Bing and media network MSN. "While the Online Services Division business has been improving, the company’s expectations for future growth and profitability are lower than previous estimates," it said.