Mountain View, Calif. — Google (NASD:GOOG) is in the midst of a Federal antitrust investigation into whether it has abused its dominance in the search-advertising business  that could be as big as we have seen since the federal government’s antitrust battle with Microsoft Corp (NASD:MSFT) in the 1990s, according to The Wall Street Journal.

The investigations, which started on Thursday in California, come just after the Wall Street Journal reported Google was about to receive a subpoena from the U.S. Federal Trade Commission (FCC) as part of a probe into the company’s Internet search business.

This isn’t the first time Google has received complaints from rival companies, as U.S. antitrust regulators have been concerned for some time about Google’s dominance in the web search industry.

While it is too early to tell if the investigations will rise to level of the Fed’s legal fight with Microsoft in the 1990s, Google has ramped up its presence in Washington, DC over the past few years, spending over $7 Million on lobbying in 2010 according to the Center for Responsive Politics and employing 30 Washington staffers and a team outside consultants and lobbyists, a sign that it is not taking this matter lightly.

“The distraction that comes from a federal investigation should not be underestimated,” commented Colin Gillis of BGC Partners, as reported by Reuters.

Related Links: (Wall Street Journal) (Reuters)