U.S. District Judge James Donato in San Francisco said in his order that Google "fell strikingly short" in its duties to preserve records. The ruling is part of a multidistrict litigation that includes a consumer class action with as many as 21 million residents; 38 states and the District of Columbia; and companies including Epic Games Inc and Match Group LLC.

The consumers and other plaintiffs are challenging Google's alleged monopoly for distributing Android mobile applications, allegations that Google has denied. Plaintiffs have claimed aggregate damages of $4.7 billion.

The judge asked the plaintiffs' lawyers by April 21 to provide an amount in legal fees they are seeking as a sanction.

Separately, the plaintiffs will have a chance to urge Donato to tell jurors that Google destroyed information that was unfavorable to it. He said he wants to see "the state of play" at a later stage in the case.

"Google has tried to downplay the problem and displayed a dismissive attitude ill tuned to the gravity of its conduct," the judge said.

A Google spokesperson on Tuesday said the company has "produced over three million documents, including thousands of chats."

In a court filing last year, Google's lawyers said the company took "robust steps to preserve relevant chats."

Lawyers representing plaintiffs had no immediate comment.

The attorneys said they were seeking instant messaging communication "on topics at the core" of the litigation, according to their filings. The lawyers said Google was deleting chat records every 24 hours and "did so even after this litigation commenced."

The judge determined Google "left employees largely on their own to determine what Chat communications might be relevant" to the litigation.

The trial is scheduled to begin in November.

Google is separately fighting claims in a U.S. Justice Department antitrust case in Washington, D.C., federal court of destroyed chat records.

The case is In re Google Play Store Antitrust Litigation, U.S. District Court, Northern District of California, No. 3:21-md-02981-JD.