Zillow.com and Yahoo! Real Estate launched yesterday an exclusive partnership that brings together the two sites and creates the largest real estate network on the web, according to comScore.

Image by Thomas Tolstrup/cultura/Corbis

Real estate agents and brokers will now have the ability to buy local advertisements on both sites with just one phone call to Zillow. Tens of thousands of industry professionals have reached Zillow’s nearly 16 million monthly unique users with advertising programs like Zillow’s Premier Agent, which allows agents to target specific ZIP code searches, and with Showcase Ads and Featured Listings, which allow agents and brokers to increase traffic to individual listings. Both of these programs will now be extended to Yahoo! Real Estate.

“We’re thrilled to be providing agents and brokers with outstanding new opportunities to extend their reach on the largest online real estate network,” says Spencer Rascoff, Zillow CEO. “One phone call can now connect industry professionals to the biggest real estate network on the web. The launch of this partnership will simplify advertising decisions and bring Zillow listings to millions of additional users every month.”

For the first time, real estate agents have the opportunity to advertise locally on Yahoo! Real Estate, one of the largest individual real estate sites on the web, gaining access to a new set of customers and clientele. Home buyers will now have access to more local listings on Yahoo! Real Estate, along with more photographs.

In addition to selling local ads, Zillow is also selling national display advertising across both sites to new home builders, real estate agents and brokers.

Zillow will also act as Yahoo! Real Estate’s exclusive provider of for-sale listings. Any for-sale listing that appears on Zillow – including many listings not found on other sites, such as for-sale-by-owner listings – will automatically appear on Yahoo! Real Estate.

“This partnership brings together the scale of Yahoo!’s audience with the depth of Zillow’s real estate listings,” Greg Hintz, head of Yahoo! Listings, said. “No other real estate websites are better suited to bring such a vast offering to agents, brokers and advertisers.”

The Yahoo! and Zillow relationship began in 2006 when Yahoo! Real Estate incorporated Zillow’s Zestimate home valuations for more than 72 million U.S. homes into its user experience.