The New York Times reports on Google's announcement that it will begin selling search ads on websites that can be viewed on mobile phones. This new product - called AdSense for Mobile - would work in the same way as the web-based system by displaying ads on mobile web pages based on keywords and site content. Advert prices will still be set through an auction bidding system and and advertisers will pay when a user clicks on its ad from the phone.

Google has been running a limited test of the system this year and this week it is opening the option to all mobile publishers in 13 countries, which are the United States, UK, France, Italy, Germany, Spain, Ireland, Russia, Netherlands, Australia, India, China, and Japan. Google says that the ads would provide a new source of revenue for publishers and could also encourage more online sites to create mobile-focused websites - an area that remains slow to develop.