Microsoft, which partners with NBC Universal on the MSNBC news and entertainment Web site, also has advertising deals withand .
Under the CNBC deal, Microsoft will be the exclusive third-party provider of display and contextual advertising for CNBC.com, which has more than 2.6 million unique monthly visitors.
"Inventory from the two sites (CNBC and Microsoft) will get aggregated together into a larger network for advertisers," said Jon Tinter, general manager of online strategy and business development at Microsoft.
Contextual ads will start appearing later this month, and display ads are expected to be showing on the site in March.
The companies would not discuss the financial terms except to say that they will share ad revenue.