June 5 (Reuters) - A closely-watched consumer class

action accusing major Las Vegas hotels of sharing price

information to artificially boost the price of room rentals is

headed back to court, after the plaintiffs on Tuesday appealed a

judge's decision to toss the case.

WHY IT'S IMPORTANT

The lawsuit, Gibson v. Cendyn, was dismissed in May for a

second time on the grounds that the plaintiffs had not shown

Wynn Resorts ( WYNN ), Caesars, Treasure Island and other hotel operators

made any pact to fix room rates.

The appeal to the 9th U.S. Circuit Court of Appeals will set

up a closely watched fight in the case, part of a wave of

antitrust lawsuits targeting companies' use of third-party

software platforms and advanced algorithms to set prices.

The hotels in the Vegas case denied any wrongdoing.

CONTEXT

None of the other pending algorithmic price-fixing cases

testing the scope of U.S. antitrust law have reached an appeals

court.

The consumers in the Las Vegas case alleged that the hotels

pooled data using Cendyn revenue management software to

illegally coordinate their room prices. The hotels countered

that they never formed any agreements with each other, and that

the software only offered recommendations.

The U.S. Justice Department has called the algorithmic

pricing cases a new "frontier" for price-fixing. In dismissing

the case, Chief U.S. District Judge Miranda Du called it relied

on a "relatively novel antitrust theory."

BY THE NUMBERS

The plaintiffs' lawyers estimated there are tens of

thousands, if not hundreds of thousands, of would-be class

members in the Vegas hotels case.

WHAT'S NEXT

The San Francisco-based appeals court will take submissions

from both sides and from interest groups that are not directly

involved in the case. A three-judge panel will hear arguments,

with a decision likely sometime in 2025.