world U.S. software giant Microsoft and Internet company Yahoo have agreed to a partnership both companies hope will change how Internet users search the World Wide Web. The agreement gives Microsoft access to the Internet's second largest search engine. But industry experts say the deal is part of a larger strategy to challenge the dominance of the Internet's biggest search engine — Google.

Every time a user goes online, invisible search engines scan billions of bits of information in a process that will ultimately help them decide which Web site to click on. These search engines are patented, complex algorithms worth potentially tens-of-billions of dollars. And, Microsoft, with its search engine, has made it clear it wants a bigger share.