The estimated price tag of the beer, which was once Britain’s most popular, is between £10m and £15m.
The sale of Bass could be followed by other small British brands including Boddingtons and Flowers.
AB InBev, created through a massive £26bn takeover two years ago, is concentrating on major international brands like Budweiser, Stella Artois and Beck’s rather than traditional ales.
Bass is brewed under contract by rival Marston’s, whose main brand is Pedigree.
Marston’s is reported to have ruled itself out of the bidding as have other players in the British brewing industry, including Wells & Young’s, Molson Coors and C&C Group.
In March AB InBev’s UK chief Stuart McFarlane said: “Our focus is on Budweiser, Beck’s and Stella, and I’m not apologising for that. I’m happy to say to the regional brewers, you take control of the cask-ale business — you do it better.”
The company earned more than expected in the first quarter of 2010 as beer sales surged in booming Brazil and forecast stronger growth in the second half of the year. A boost from the World Cup is also expected.