The U.S. Federal Trade Commission and nearly every U.S. state sued Facebook Inc on Wednesday, saying that it broke antitrust law and should potentially be broken up.

With the filing of the twin lawsuits, Facebook becomes the second big tech company to face a major legal challenge this fall.

The FTC said in a statement that it would seek an injunction that "could, among other things: require divestitures of assets, including Instagram and WhatsApp."

In its complaint, the coalition of 46 states, Washington, D.C. and Guam also asked for Facebook's acquisitions of Instagram and WhatsApp to be judged to be illegal.

The U.S. Justice Department sued Alphabet Inc's Google in October, accusing the $1 trillion company of using its market power to fend off rivals.

The lawsuits are the biggest antitrust cases in a generation, comparable to the lawsuit against Microsoft Corp in 1998. The federal government eventually settled that case, but the years long court fight and extended antitrust scrutiny prevented the company from thwarting competitors and is credited with clearing the way for the explosive growth of the internet.

Facebook shares fell as much as 3% after the news before paring losses and were last down 2%.