MOUNTAIN VIEW, Calif. - Google plans to stop selling advertising on broadcast radio at the end of May. The retreat is the latest example of how the recession is forcing the Internet search leader to reassess its ambitions beyond the online ad market.

Thursday's announcement could lead to up to 40 layoffs among Google's work force of 20,200 employees, the Mountain View, Calif.-based company said.

The decision to stop selling ads for broadcast radio stations comes less than a month after Google scrapped its effort to sell ads for newspapers. The company expanded into radio advertising three years ago.

Google said it still intends to place ads on television.