The mutual, which offers a range of insurance, pension and investment products, has approached agencies through the intermediary Agency Insight ahead of a pitch.
It last reviewed its ad business in 2008 after the closure of Shop, its incumbent agency at the time. Since then, it has worked with agencies including Farm Communications, which created a campaign using the strapline: "We do right by you."
Walker Media, which has held the NFU Mutual media account for the past ten years, is thought to be unaffected by the ad agency review.
NFU Mutual, which was launched by farmers, is affiliated with the National Farmers Union but also sells products to those outside the farming community.
The company celebrated its 100th anniversary in 2010 and manages more than £12 billion in assets on behalf of its members.