The tension among search engines escalated Wednesday afternoon when Google (GOOG) introduced Google Instant, a feature that tries to predict what users are searching as they re typing.

Now, as a user types a word in Google s search field, results pop up without loading a new page. If the word or search term changes as the user continues typing, the search results refresh automatically.

The feature, which Google says can remove two to five seconds from the average search, became available immediately on Wednesday.

The new search tweak represents the latest attempt by the behemoth to chip away at the growing competition from other search engines like Microsoft s (MSFT) Bing and Yahoo (YHOO), with whom Microsoft recently partnered, as they battle for visitors and advertising dollars.

"We find it interesting to note that Microsoft's Bing search engine launched its real time service, Bing Social, last June, and it has a much richer base of features (e.g., one can search just Facebook)," Lou Kerner, an analyst at Wedbush, wrote in a report. In late August, Google introduced a new feature on its general search page for searches through blogs.

While competition for more users is growing among the three companies, market share data suggests Google still holds a solid lead. Microsoft accounted for 11% of search market share in July, while Yahoo accounted for 17.1%, according to comScore s most recent data. Google was comfortably ahead of the pack at 65.8%. These numbers have remained mostly unchanged since January.

The new search feature could widen Google s lead and lift its profits by making its searches particularly complex queries involving multiple search terms more efficient, drawing more advertising dollars to pad its $24 billion revenue stream, which has been mostly stagnant since the beginning of the year.

The feature could also help curb new competition from social networks. Earlier this month, Facebook improved its own search engine by providing results based on articles that a user s friends have "liked" on news sites.

"The introduction of this new functionality comes on the heels of Facebook's recently approved 2004 patent application for 'ranking search results based on the frequency of clicks on the search results by members of a social network who are within a predetermined degree of separation,'" Kerner wrote. "The patent may prove useful as Facebook battles Google, which is likely to include social click-behavior as part of its page ranking algorithm."