The list of four competing agencies includes incumbents on the business, WPP's MediaCom, Omnicom's PHD, Publicis-owned Zed Media and Interpublic agency Universal McCann.
The agencies will now compete for the media account for the Prudential and Egg investments business.
MediaCom currently handles the £12m Egg media planning and buying business while the £8m Prudential account currently resides at PHD. Zed Media handles the media account for Prudential-owned M&G Group, which is also believed to be part of the review.
The pitch was called at the end of last year in the wake of Prudential acquiring the final 21.7% stake in Egg that it did not already own, and is being conducted by Egg's chief marketing director Alison Wright. She is believed to be in favour of consolidating the account into a single agency.
The creative account is handled by WCRS, where Wright was formerly business director on Abbey. She is also a former managing director at Manning Gottlieb OMD. Media auditor Billetts is overseeing the pitch process for the business.
Prudential turned down a £17bn takeover offer for its business from Aviva in March.
Wright was not available for comment.
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