Google made its biggest acquisition to date on Tuesday as it branched out into radio advertising with a deal that could cost it as much as $1.24bn.

The purchase takes the search engine company into the broadcast field for the first time, and signals its ambition to extend the reach of its internet-based advertising network as digital distribution takes hold across a wider range of media.

The initial purchase price for dMarc Broadcasting, a US private company, will be $102m in cash. Google said it would pay up to $1.136bn more over the next three years if dMarc hits targets that have been set for product integration, net revenues and advertising inventory levels.

Find out how Google intends to integrate Adwords into radio advertising at http://msnbc.msn.com/id/10892278/.