The technology giant has approached several networks from four holding companies. Although the review is being run out of Microsoft's US head office, the UK market is considered to be a European hub, and domestic agencies will be asked to submit both work and figures.
The company is looking for one network to run all of its relationship marketing programmes globally.
The successful network would be required to produce all of Microsoft's direct marketing and sales promotion material and put in place an international CRM system to manage the responses that this material generates.
Microsoft is emulating its rival IBM, which uses one network for all of its below-the-line needs. OgilvyOne has held the global IBM account since 1994, which it runs from its Paris office.
Microsoft's £10 million UK account is currently held by Chemistry. The agency took the business from the incumbent, EHS Brann, in February this year following a four-way pitch conducted through Agency Assessments.
The company has recently reviewed the direct marketing account for its game console, X-box. The £3 million brief for the UK and Europe, the Middle East and Africa was given to Tequila London after a competitive pitch.
The review does not affect Microsoft's above-the-line creative account, which is held globally by McCann-Erickson.