Shares of Google Inc. were up 0.3 percent at $581.70 on the Nasdaq stock exchange this afternoon following the Justice Department’s approval of the company’s purchase of ITA Software Inc., Reuters reported.

But Google must license and upgrade the ticketing software it intends to purchase, as well as establish firewalls to hide proprietary information, as it plans to launch a new service providing flight search results that would compete with Internet-based travel services.

Google said last July that it would buy ITA Software for $700 million in cash, a move that rattled travel websites such as Kayak and TripAdvisor because of concerns that they could be deprived of ITA’s software.

ITA’s products must remain available to Google’s rivals, the Justice Department said.

Google operates the world’s largest search engine.