In a move that expands Google's advertising efforts beyond magazine glossies, Google will now sell advertisements that appear in the print editions of 50 major newspapers.

Many of the largest newspaper companies, including Gannett, The New York Times Company, The Washington Post Company and Hearst will being testing the system later this month. The trial will last three months.

The basics: Google will sell the remnant ad space that would otherwise run house ads for the paper. Ostensibly tha ad buyers will be small businesses that the newspaper wouldn't be able to service anyway. The advertisers log into the AdWords system and are presented with a list of participating papers and available ads. They can then enter a bid for a certain type of advertisement, specifying the section and date range. Newspapers in turn see these bids and accept the ones they want.

There is no auction system because papers often don't know their ad space amount until the last moments before going to press. With the print magazine test, Google bought ad space beforehand and then sold it to advertisers.

From Businessweek, this nugget: One common, if slightly paranoid, concern of print executives was that Google's auction system would migrate into ad buying, which could in effect allow Google to set publishers' ad rates.