Today’s launch follows the US roll-out in November 2009.
A Google blog, today, said: "With product extensions you can show users the products from your site that are most relevant to their current query.
"You're charged the same cost-per-click (CPC) whether a user clicks on your main text ad or any of the offers within the product extensions plusbox. However, you won't be charged if a user simply expands the plusbox without clicking through to your site.
"Advertisers using product extensions have found that the additional product information has helped improve the performance of their search campaigns.
"For example, SonyStyle.com reported seeing a 9% increase in conversion rates for their ads with product extensions."