The company is believed to be talking to Grey, McCann Erickson, WCRS and Rainey Kelly Campbell Roalfe/Y&R about the review.
A detailed brief has not yet gone out to agencies, but it is expected to be a business-to-business assignment promoting Nokia Networks to large corporations.
A below-the-line pitch is also underway for the same account. The brief focuses on persuading large corporations to use its platform rather that of telecommunications rivals including Vodafone or O2. However, the identities of the agencies involved in the direct review have not been revealed.
The main phone account is handled around the world by Grey Worldwide, which was acquired this week by WPP.
It is now unclear if WPP's RKCR will continue to fight for the account.
WCRS joined Nokia's roster in July, when it was picked to handle the Vertu luxury mobile phone brand's £5 million global account. The agency saw off Mother and Quiet Storm in a pitch.
A global reorganisation saw Nokia divided into four divisions in February: Nokia networks, phones, enterprises and multimedia.