ITA was founded in the 1990s by computer scientists from the Massachusetts Institute of Technology. The company revolutionized the ability of consumers to find the cheapest fares by making it easy to compare fares among airlines. It has licensed its product widely, and customers include companies like American Airlines and Continental Airlines. Web sites like Hotwire, Kayak, Orbitz and Farecast, which is now part of Microsoft’s Bing search service, also use ITA’s software.

Mr. Schmidt said that Google would honor all existing agreements and seek to add new partners.

“Airline travel and search are a perfect opportunity for more innovation, more investment and more interesting products,” Mr. Schmidt said. “The whole idea is to give people more of what they want, and more information when they are searching.”

Companies that may lobby against the deal include Microsoft, Expedia and Kayak; reservation networks like Travelport, Sabre and Amadeus; and possibly even some airlines. The deal has been rumored in the travel press for months.

Airlines could be concerned “how Google will present this information, how will it appear in Google search and whether they will have to pay for the results,” said Henry H. Harteveldt, an analyst at Forrester Research. “What airlines do not know is whether they will have to bid to have their own Web sites listed against the travel agencies.”

Google declined to predict what kinds of services might result from the acquisition. In the conference call, Marissa Mayer, Google’s vice president for search products and user experience, talked about being able to answer more open-ended travel queries, like “Where can I get within seven hours and within this price?”

“Travel is one of the hardest problems around, both in the way people like to address queries and the accuracy and speed which you need to give people the results they are looking for,” she said.

Rick Seaney, the co-founder of farecompare.com, which uses ITA’s technology, said the deal might prompt some antitrust concerns, especially from Microsoft.

“We have got a couple of months to contemplate this,” Mr. Seaney said, citing the expected lengthy review process. “We don’t really know what it all means yet, other than they will continue on with their existing relationships.”