The news is a blow to Mediaedge:cia, the global incumbent. Sony Ericsson is in the process of drawing up a shortlist of networks to pitch.
The company, which is a 50:50 joint venture owned by Sony of Japan and Ericsson of Sweden, is attempting to challenge Nokia's stranglehold on the market.
It sold 8m phones in the last quarter of 2003, 13% more than a year ago, and was able to report a second consecutive quarter of profits after a run of losses.
The success of the T610 mobile phone, which combines Quickshare imaging and a built-in Music DJ feature, helped boost its sales.
The T610 was promoted with a global television, print and online campaign created by Bartle Bogle Hegarty and Dare Digital, with media planning and buying by MEC.
The TV spot followed the journey of a phone as it was passed between people, with each recipient reacting differently to the images on the screen. The soundtrack featured Marianne Faithfull in collaboration with Blur.
However, the improved sales comes against a market growth of 20% in the last quarter of 2003. Sony Ericsson is estimated to have a market share of about 6% and is the number five global mobile manufacturer.
The review sees Sony Ericsson become the second mobile handset manufacturer to review its media business in the past three weeks; Panasonic is currently creating an agency shortlist for its £15m European account.
At the beginning of March, Sony Ericsson reshuffled its UK and Ireland marketing team by hiring Ben Padley as its head of marketing.
He replaced Peter Marsden, who was promoted to managing director of the division at the start of the year.
In a bid to improve its fortunes last month, Sony Ericsson announced it planned to increase its share in Symbian, the consortium of handset manufacturers, which supplies much of the software powering mobile phones, set up as a rival to Microsoft's offering.
The move was triggered by Psion's decision to sell its 31.1% stake to Sony Ericsson's arch-rival, Nokia. Nokia is already Symbian's largest shareholder with 32.2%.
Reports suggest Sony Ericsson will pay about £37m for an 8.6% share of the venture, ensuring it can block any major changes to Symbian and prevent it being assimilated into Nokia and reverting to a software developer.
No one at Sony Ericsson was available to comment as Campaign went to press.
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