The list includes OgilvyOne, Hall Moore CHI, Tequila, Archibald Ingall Stretton and Rapier, as well as the incumbents, EHS Brann and WWAV Rapp Collins.
Both incumbents, which have shared the account for the past 12 years, have been on six-month notice periods since the review was called back in November last year.
The pitch will take place next week, with a decision expected in three weeks.
The review was initially handled through the AAR but will now be managed in-house by Chris Brocklehurst, the brand manager at British Gas.
Industry insiders speculate that although British Gas plans to consolidate the account into one agency, should none of the agencies satisfy its needs individually, the account will be split up between two or three agencies.
The above-the-line advertising, held by Clemmow Hornby Inge, is unaffected by the review. British Gas will also continue to use Carat.
British Gas refused to comment on the review.