The box, which is labelled "Sponsored", appears below the yellow advert section and above the natural search results and is being rolled out across related search terms.
The search is run by Beatmyquote, a comparison website bought by Google in March 2011. It had been running a test comparison tool at the top of the advert box, but a spokesman for Google said the new tool, unveiled on 30 April, was "more visually pleasing and transparent" for consumers.
The results of the search shown in the box are companies that have partnered with Google, and consumers who click on the information button are told that the search engine may get a commission if they buy one of these products.
Anyone who clicks through to the "advanced" search can opt to search the whole market, which means companies not in a commercial relationship with Google also show up.
John Paleomylites, product management director at Google, said: "The enhanced service is now easier to use for consumers and will provide higher quality traffic for advertisers. We will introduce this improved design layout for searches around credit cards, current and savings accounts in the UK."
SOURCE: THE GUARDIAN