Update: The Shoe Drops: Google Receives Formal Notification Of Review By FTC

As expected, the Federal Trade Commission has begun its formal investigation of Google’s business practices. In a blog post today, Google fellow Amit Singhal wrote that the company yesterday received formal notification from the agency that it would be conducting an inquiry.

Though Singhal writes that “it’s still unclear exactly what the FTC’s concerns are,” reports in recent days have pointed to Google’s core search advertising business as a concern. According to the Wall Street Journal, the investigators will look into whether Google somehow is unfairly dominating the sphere, at the expense of competition.

Google today filed a one-line disclosure with the Securities and Exchange Commission, which pegged “search and advertising” as the areas of FTC interest:

“On June 23, 2011, Google Inc. received a subpoena and a notice of civil investigative demand from the U.S. Federal Trade Commission (FTC) relating to a review by the FTC of Google’s business practices, including search and advertising. Google is cooperating with the FTC on this investigation.”

The rest of Singhal’s blog post, while not illuminating anything about the investigation itself, provides some insight into Google’s likely defense against accusations of unfair dominance. The post — and an accompanying press section titled “Facts about Google and Competition” — lays out Google’s user focus and how hard it works to develop better products, implying that this, not unfair competition, is why Google dominates search.

We’ll have more on the FTC investigation in the next few days, so be sure to come back to Search Engine Land for more. In the meantime, for an overview of federal investigations of Google see Googleopoly: The Definitive Guide To Antitrust Investigations Against Google.