Facebook has started testing search ads, as part of a new strategy to turn around its declining ad revenues.

The social network is testing a new search advertising concept with a small number of advertisers in the automotive, ecommerce and retail sectors in the US and Canada. The concept involves inserting news feed ads into the search function of the site, although Facebook is being quiet on the specific details of how the model works.

Facebook last trialled search ads in 2012, although the idea was shelved just a year later, and is looking for new advertising revenue sources as it faces competition from Google, Amazon and its other social media brand, Instagram.