The government filed suit against Intel Corp on Wednesday, alleging that the chip giant illegally used its dominance of the market for a decade to stifle competition and strengthen its monopoly.

The Federal Trade Commission, one of two U.S. agencies that enforces antitrust law, accused Intel of trying to shut its competitors out of the market.

Intel has engaged in a deliberate campaign to hamstring competitive threats to its monopoly, said Richard Feinstein, director of the FTC's Bureau of Competition.

It's been running roughshod over the principles of fair play and the laws protecting competition on the merits.

Intel makes 80 percent of the world's central processing units, the brains of personal computers, and has been accused by other antitrust bodies and rivals such as Advanced Micro Devices Inc of acting illegally to maintain that dominance.

In early November, New York Attorney General Andrew Cuomo filed suit against Intel, accusing it of threatening computer makers and paying billions of dollars in kickbacks to maintain market supremacy.

Regulators in Asia and Europe have taken action against Intel because of controversial pricing incentives.

In Brussels, the European Commission, which enforces antitrust law in Europe, fined Intel $1.2 billion in May 2009 and ordered it to change certain business practices.

In June 2008, South Korea fined Intel some $26 million, finding it offered rebates to PC makers in return for not buying microprocessors made by AMD.

Japan's trade commission concluded in 2005 that Intel had violated the country's anti-monopoly act.

In 1999, the FTC and Intel settled charges that the chip maker used its market power to defend its dominance of the microprocessor market.

(Reporting by Diane Bartz; Editing by Ted Kerr)