Google is shutting down its Audio Ads and Adsense for Audio products. It is also making plans to sell Google Radio Automation.

About 40 employees working in Google's broadcast radio advertising sector can expect to lose their jobs. The move comes a month shy of Google's decision to shut down its print ad business. In January, services like Dodgeball, Jaiku and Google Video, were either shut down entirely or suffered cessation of further development.

Two years ago Google acquired dMarc Broadcasting for $102 million. The technology underpins both businesses; but in the time since, Google failed to ramp up adequate radio ad inventory to justify the investment.

The Audio Ads program opened to all AdWords advertisers in 2007. Analytics features were added in March 2008.