Google today acknowledged receiving a so-called "second request" from the Justice Department for information as it considers the search giant's plans to buy Motorola Mobility for $12.5 billion.
Google made the disclosure in a blog post this afternoon, saying the request was for "more information" in order to continue the review.
"While this means we won't be closing right away, we're confident that the DOJ will conclude that the rapidly growing mobile ecosystem will remain highly competitive after this deal closes," Google Senior Vice President Dennis Woodside wrote in the post. "We'll be working closely and cooperatively with them as they continue their review."
The move is likely to prolong, and could potentially complicate, the review process.
Woodside dismissed the request as "pretty routine." And he pointed to a previous second request that Google received a year ago, shortly after it announced plans to acquire travel data provider ITA Software.
But while the Justice Department ultimately approved Google's acquisition of ITA, the agency compelled Google to agree to certain conduct. Regulators required Google to continue licensing ITA's travel technology to rivals for five years on "reasonable and nondiscriminatory" terms, and forward to the agency any complaints the company receives from travel competitors upset about where they land in Google's search rankings.
Moreover, second requests are perhaps less routine than Woodside suggests. According to The Wall Street Journal, about 4 percent of all deals last year received a second request from U.S. antitrust agencies.
In a regulatory filing, Motorola acknowledged receiving a second request as well.
"The companies intend to cooperate fully and respond expeditiously to the DOJ," the company wrote in its filing. "The transaction is currently expected to close by the end of 2011 or in early 2012."
There seemed little doubt that regulators would look closely at the deal when it was announced last month. The Federal Trade Commission began an antitrust investigation into the search giant's business in June. And a week prior to the announcement of the Motorola deal, the Journal reported that the FTC was including Google's Android mobile operating system in that investigation over concerns that the company was preventing handset makers from using rival technology.
Just last week, Google Executive Chairman Eric Schmidt faced tough questions at a Senate hearing looking into the company's business tactics.
"We know that close scrutiny is part of the process and we've been talking to the U.S. Department of Justice over the past few weeks," Woodside wrote in his post.
It seems likely that those conversations will continue for a bit longer than Google might otherwise have hoped.
Updated with more details and analysis at 3:45 p.m. PT.