Google entered the radio advertising business with great hopes, but the internet search giant pulled out on Thursday.

The Mountain View, Calif.-based company said it will stop selling advertising on broadcast radio as of May 31.

The radio project, Google Audio Ads, failed to live up to expectations, Susan Wojcicki, a vice president for product management, said in a blog post.

While we've devoted substantial resources to developing these products and learned a lot along the way, we haven't had the impact we hoped for, she wrote.

The announcement could lead to up to 40 layoffs among Google's work force of 20,200 employees.

It was the second time in two months that Google has abandoned a program meant to expand its advertising business offline, suggesting that the company's ad selling model may be more limited to online than it previously expected. Three weeks ago, Google ended its Print Ads program, which sold spots in newspapers.

Google had hoped to transform the way radio ads were done by making them more targeted towards a specific audience

The company's chief executive, Eric E. Schmidt, said he expected a day to come when they would have more than 1,000 employees working within a flourishing radio advertising business.

Wojcicki said Google would apply some of its radio advertising technologies to selling ads on online audio programs.

Meanwhile, Google said it still intends to place ads on television.