Google has announced an agreement to acquire airline data firm ITA for $700m.
The announcement comes after a bidding war over the company between Google, Microsoft, Expedia and Kayak, according to US reports.
The acquisition is crucial to Google's plans for a service to handle airline-related questions, such as flight prices, times and availability.
"While online flight search is rapidly evolving, we think there is room for more competition and greater innovation," said Marissa Mayer, vice-president, search products and user experience at Google in a blog post.
Once Google has acquired ITA, the firm will work on creating new flight search tools that will make it easier to search for flights, compare flight options and prices, and buy tickets, Mayer said.
Google said it would honour all existing agreements, which include one with Microsoft to supply data for its Travel service within its Bing search engine.
But Google's plans to create flight search tools on Google.com could upset the entire $132bn-a-year air travel industry as well as its rival Microsoft, according to the New York Times.
The deal is another significant step by Google away from pointing searchers to the most relevant websites to giving information directly to users, the paper said.
Like the recent acquisitions of AdMob and Doubleclick, the latest deal is likely to face intense scrutiny by US competition authorities give it the go-ahead.
US legal experts have said that every time Google makes an acquisition, it reinforces the argument that the company is trying to acquire other companies that may present potential threats to its dominance of paid search.