Microsoft is planing to sell online marketing agency Razorfish, which it acquired as part of a $6bn takeover of aQuantive in 2007.
Microsoft has appointed Morgan Stanley to find potential buyers, which could include Omnicom, WPP and French marketing company Publicis Groupe, according to the Financial Times.
Formerly known as Avenue A/Razorfish, the agency is one of the largest digital agencies, with 2,000 employees. Its clients include Dell, Audi, Disney and Nike.
One analyst cited in the FT report estimated Razorfish could be worth $600m to $700m, based on sales of about $400m last year and profit margins for similar businesses of around 13%.
Microsoft declined to comment on the proposed sale.
Analysts said although Razorfish was initially considered important to promote Microsoft's rich media and video plug-in Silverlight, it is now seen as a conflict of interest with Microsoft Advertising.