The internet services provider (ISP) is understood to be considering its options to see what benefits it can gain from centralising its account across Europe.
The company is only in the first stages of the review and could still keep separate agencies in the UK, France and Germany.
Aegis-owned Vizeum has also worked with AOL in France and is keen to capture the AOL account in further European countries.
The UK account is worth more in billings than any of the other European accounts. The UK is the company's leading market outside of the United States.
The marketing department at the company has been through a recent shake-up following the resignation of its vice president for marketing, Sharon Lang.
Lang took up a place in consultancy, while former Orange marketer Timothy Ryan took the newly-created role of brand director.
The advertiser announced a shake-up of its £6m direct marketing account in May, holding chemistry meetings with several below-the-line agencies.
The internet service provider has more than two million customers in the UK and has been focused on a marketing drive to increase take-up of its broadband services across Europe.
AOL recently allocated £20m for an advertising campaign to launch its latest 9.0 internet access package.
The April 2004 launch for 9.0 included the largest retail and online campaigns in AOL UK's history. The campaign included spend on television, print, radio and outdoor.
AOL has faced increasing pressure for online consumers with competition from Yahoo!
MSN, Google and Tiscali. It also had to deal with the divorce of its brand name from the AOL Time Warner portfolio.
An AOL spokesman was unavailable for comment.