As Google continues to slog it out with the Justice Department over its pending acquisition of travel search company ITA Software, Microsoft continues to improve Bing's travel functionality. In doing so, Microsoft is sending a not-so-subtle message to Google: We're winning the travel search battle.

Last week Bing paired Autosuggest Flight Prices with its Price Predictor technology, giving users suggestions on whether to buy tickets now or wait for a better deal. Not only is the autosuggest feature strikingly similar to Google Instant, the Price Predictor tool relies on airfare schedules and pricing collected by--guess who?--ITA Software.

Now Microsoft has officially chosen Kayak.com as its travel search partner, which stands to enhance Bing's power in the travel search market. "When combined with Bing's own tools and technologies such as Price Predictor, rate indicator, flexible search tools and Flight Answers, we are really doubling down on giving customers the tools to make faster, more informed travel decisions," writes Krista Pappas, Bing's Global Travel Industry Director.

Microsoft and Kayak, among many other travel-related Internet companies, are members ofFairSearch.org, a coalition that opposes Google's planned acquisition of ITA Software and asks the U.S. government to block it on the grounds that it will hurt competition and drive up prices. Microsoft makes this alliance very clear-it appears at the bottom of its travel blog post, in bold.

There's no word on when or if Google will wrap its hands around ITA Software, so the battle to gain prominence in online travel searches is nowhere near complete. However, based on Bing's progress, Microsoft has a head start.

By Brennon Slattery, PCWorld