Google Inc.’s $700 million takeover of flight-information provider ITA Software Inc. is set to face regulatory scrutiny because of Google’s large market share in Internet search, UBS AG analyst Brian Pitz said. Google’s acquisitions of AdMob Inc. and DoubleClick Inc. took about nine months to get approval, New York-based Pitz said today in a research note. Google, owner of the world’s most popular search engine, announced the ITA acquisition yesterday.

The purchase will probably help Google compete against travel-information services from rivals including Microsoft Corp.’s Bing and Kayak.com, Pitz said. Though ITA has focused on airlines, it will probably expand to hotels and rental cars, said Pitz, who recommends investors buy Google shares.

Google had more than five times the online search share of Microsoft’s Bing in the U.S. in May, according to ComScore Inc., a Reston, Virginia-based researcher. Microsoft has lured users partly through travel-related tools including features that predict ticket-price changes.

Andrew Gavil, a law professor at Howard University in Washington, said it’s unlikely the ITA acquisition will face “significant antitrust concerns.” The purchase is an extension of Google’s business and not an example of one competitor buying another, a circumstance that would draw scrutiny from authorities, Gavil said in an interview.

Eric Schmidt, Google’s chief executive officer, said yesterday that he suspects there will be a “significant review” of the deal. He declined to speculate on the timing of when the acquisition will close. Google, based in Mountain View, California, fell $2.94 to $436.55 at 4 p.m. New York time on the on the Nasdaq Stock Market. The shares have lost 30 percent this year.