WASHINGTON - Dozens of states led by New York asked a U.S. federal appeals court on Friday to reinstate an antitrust lawsuit filed against Facebook.

"Facebook is a monopolist that has exploited its immense market power to crush competition. Through an ongoing course of conduct to 'buy or bury' nascent competitors, Facebook has maintained a monopoly that harms its users and the public at large," wrote lawyers for New York and other states in a filing to the U.S. Court of Appeals for the District of Columbia.

Facebook owner Meta Platforms Inc said the states were wrong to ask for the district court dismissal to be reversed. "There are no grounds for overturning that decision in the court of appeals," a Meta spokesperson said in a statement.

New York Attorney General Letitia James said Facebook was bad for consumers. "Time and again, the social media giant has used its market dominance to force small companies out of business and reduce competition for millions of users," she said.

The group, made up of 46 states, Guam and the District of Columbia, argued that U.S. District Judge James Boasberg of the District of Columbia erred in ruling they had waited too long to file the lawsuit.

They argued that states are allowed delays that private plaintiffs are not. They also argued that if the court determined they did wait too long, states are allowed deference that others are not because of their role in protecting the public interest.

Boasberg had also thrown out a related Federal Trade Commission complaint against Facebook in June but allowed the agency to refile the case. It did so, and Boasberg said this week the case would be allowed to go forward. 

Both the FTC and the states had asked the court in 2020 to order Facebook to sell Instagram, which it bought for $1 billion in 2012, and WhatsApp, which it bought for $19 billion in 2014. 

The lawsuits followed years of investigation of the four biggest U.S. tech giants, as well as lawsuits against Facebook and Alphabet Inc's Google. 

(Reporting by Diane Bartz ind Washington and Elizabeth Culliford in New York Editing by David Gregorio and Matthew Lewis) ((Diane.Bartz@thomsonreuters.com; 1 202 898 8313;))