Major Internet sites are showing a strong and growing interest in the advertising business, and traditional ad firms are starting to get worried

Google has been leading the way, building on its online ad strength by striking deals to sell advertising in traditional media like newspapers and radio. Meanwhile, eBay is developing an ad-buying system for TV spots for a group of large advertisers like Wal-Mart. And yesterday, Yahoo announced a deal with 176 newspapers that did not include offline ad sales, although newspaper executives did not rule that out.

Ad executives say it is hard to know where Google and the other Internet giants will stop.

“The fox is in the henhouse and it’s going to gobble a good part of this business up before anybody realizes they’re history,” said Gene DeWitt, president of DeWitt Media Solutions.

Traditional media companies are increasingly linking up with the online giants that have been stealing their customers and advertisers. The traditional companies — like newspapers, magazines and television and radio networks — are hoping they can reverse their fortunes and share in some of the Internet success.

Get the full story at The New York Times