Microsoft unveiled this Monday a search distribution agreement with Sun Microsystems meant to help them boost their share on the search market, where they’re lagging behind Google and Yahoo on a modest third spot.

Following the agreement, which is effective as of yesterday, Internet Explorer users downloading Sun’s Java Runtime Environment will be given the option to also download the MSN Toolbar with a Microsoft Live Search feature, and will have one click access to Windows Live Hotmail and Windows Live Messenger.

According to Yusuf Mehdi, senior vice president of the Online Audience Business at Microsoft, the agreement is an important milestone in the company’s strategy to ensure broad-scale distribution of their search offering for millions of people.

“With the vast array of Java software-based Web applications that are downloaded every month, this deal will expose Live Search to millions more Internet users and drive increased volume for our search advertisers,” Mehdi said.

Microsoft is counting on the popularity of the Java software platform to reach as many users as possible. To be more precise, the company is targeting over 800 million Java users around the world, which account for 91 percent of Internet-connected PCs worldwide.

The goal has been stated very clearly: to provide the millions of users with “compelling and immersive business and consumer solutions powered by the Java technology,” as Sun Microsystems’ executive vice president Rich Green said, expressing confidence that the agreement will prove successful.

After failed negotiations with Yahoo earlier this year, Microsoft decided to choose another path to increase its share on a search market clearly dominated by Google for years. The decision to work with Sun came of course as a surprise for all those who remember the 2004 episode between the two companies.