Five days ago, Google and ITA Software announced that they’d reached a "definitive agreement" covering an acquisition.  Only – if you hadn’t already guessed – it looks like a government agency may have a thing or two to say, as a new report indicates that antitrust regulators will take a close look at the transaction.

The main concern is that Google might eventually withhold flight data (which ITA provides) from its search rivals (Bing is one ITA customer).  The search giant’s only promised to honor existing agreements so far.

As a result, there appears to be something of a competition over who will question Google’s intentions.  Brad Stone reported this afternoon, "According to one person familiar with the agencies that oversee federal antitrust law . . . discussions are under way between the Federal Trade Commission and the Department of Justice to see who will get to review the deal.  According to this person, either agency would ‘dig in pretty aggressively.’"

Stone next speculated, "Google likely favors an F.T.C. review of the deal, considering that the agency previously approved two of its previous purchases, of DoubleClick and Admob.  But the Justice Department, which opposed Google’s settlement in a case involving the scanning of books whose rights holders are unknown, and its proposed search deal with Yahoo, is the more likely candidate, because it typically handles air travel deals."

Brace for another round of "do no evil" blog posts authored by Google execs, then.  Perhaps with a legitimate concession or two thrown in for the sake of speeding up the review process.

Just don’t count on Google’s travel search capabilities radically improving anytime soon considering that the matter of jurisdiction hasn’t even been settled yet.