WASHINGTON – Federal regulators have sharpened their antitrust attack against Facebook, alleging in a revised complaint Thursday that the social network giant pursued a laser-focused strategy to “buy or bury” rivals to suppress competition.

It is the Federal Trade Commission’s second run at the company.

A federal judge in June dismissed antitrust lawsuits brought against Facebook by the agency and a broad coalition of state attorneys general that were among multiplying efforts by federal and state regulators to rein in tech titans’ market power.

The FTC again is seeking remedies that could include a forced spinoff of Facebook’s popular Instagram and WhatsApp messaging services, or a restructuring of the company.

The agency’s lawsuit last December alleged Facebook engaged in a “systematic strategy” to eliminate its competition, including by purchasing smaller up-and-coming rivals like Instagram in 2012 and WhatsApp in 2014.

Facebook said the FTC was attempting to revive a meritless lawsuit and said it will vigorously defend itself against what it said is an effort to rewrite antitrust laws.

“There was no valid claim that Facebook was a monopolist – and that has not changed,” the company based in Menlo Park, California, said in a prepared statement. “Our acquisitions of Instagram and WhatsApp were reviewed and cleared many years ago, and our platform policies were lawful.”