Google on Thursday will launch a new advertising technology that will allow publishers to incorporate text ads into online videos in a move long awaited by the industry.

The launch marks the search group’s most ambitious attempt yet to make money by selling ads that appear inside of online video clips. It comes nearly 18 months after Google acquired YouTube, the world’s biggest online video site, for $1.65bn.

Under the new system, advertisers will pay to have their messages appear inside of online videos across the web.

Google’s video ads will take one of two forms: banner ads, which will run at the top of the video screen, and “overlay” ads, which will be inserted on top of videos as they play. The ads will be selected based on the content of the video and the web pages on which they appear.

While several other companies have already launched advertising networks designed to capitalise on online video, Google’s entry into the market could be a new phase of development for the fast-growing internet segment.

Google is the world’s leading internet search group. Its ad network accounted for 23.7 per cent of the $7.3bn spent on online ads in the US last quarter, according to a recent report by IDC, the market research group.

Google’s video ads will be served by a number of launch partners, including the online video networks YuMe and Brightcove.