Also, it is considering its options on the media business for the RAC business, which it recently acquired and is held by Vizeum.
Aviva has held a series of "chemistry" sessions with leading agencies, regarding its insurance business. An appointment on Norwich Union is expected by the end of the year, but Aviva will be now reviewing media activities across the group following the acquisition of the RAC.
A spokesman for Norwich Union said: "We are looking at all of our agency relationships as part of a review process due to the integration of the RAC into the company."
Aviva purchased the rescue service for £1.1bn in March this year and is believed to be looking at the possibility of centralising both the RAC and Norwich Union accounts. Aviva said it was looking to "exploit the brand strength" of the rescue service and sell its products to the company's 6.7 million members.
The umbrella brand Aviva is the world's sixth largest worldwide insurance firm and has 60,000 employees serving 30 million customers globally. The firm was formed from the merger of the CGU Group and Norwich Union in 2000 and rebranded to Aviva in July 2002. The firm had sales of £33bn during 2004 and managed £291bn of assets for its customers. The RAC deal complemented the company's motor insurance arm, Norwich Union Direct, a prime media spender within the organisation, placing £16m of media during 2004.
The company has faced challenges through high-profile campaigns from insurers and major supermarket brands, which now offer their own insurance services for consumers. Aviva has said it wants to become "the Tesco of the insurance sector".
Should the company centralise its business, it will be looking for an agency with a strong direct mail department to complement its direct strategies.
Norwich Union's spokesman added: "We will be inviting our current agencies to pitch for the business and several others, which we can't disclose at this stage. The pitch document will be delivered by September and we will be looking to award the business by the end of the year."