Adds details from decision, separate Robinhood order, comments, DraftKings and FanDuel parent stock prices, byline

By Jonathan Stempel

Nov 26 (Reuters) - A federal judge said the prediction markets platform Kalshi is subject to Nevada gaming rules, impeding its ability to expand its sports betting business.

In a decision made public on Tuesday, Chief Judge Andrew Gordon in Las Vegas federal court sided with the Nevada Gaming Control Board, and lifted an April 9 injunction that had allowed Kalshi to continue offering contracts related to sports events on its exchange.

Kalshi is appealing. A lawyer for the company declined to comment on Wednesday.

Gordon separately rejected online trading platform Robinhood's HOOD.O request for a temporary order allowing its customers to trade sports-related contracts on Kalshi's exchange.

Robinhood said on Wednesday it will temporarily stop offering those contracts in Nevada on December 1, "while we work with the court toward a resolution."

Shares of sports betting companies DraftKings DKNG.O and FanDuel parent Flutter FLTRF.L rose after Gordon ruled.

Prediction markets let people bet on outcomes of events such as elections and show business awards, often focused simply on who wins and loses rather than the degree of victories or losses.

Though 39 U.S. states and Washington, D.C. have legalized sports betting, many states and tribal gaming authorities have sought to exclude prediction markets platforms.

Nevada has outsized influence, as a leader in gambling regulation and because gaming is particularly important to its economy.

JUDGE SAYS PUBLIC INTEREST SUPPORTS LETTING NEVADA REGULATE

Known for offering bets on elections, Kalshi argued it was a so-called designated contract market subject to the U.S. Commodity Futures Trading Commission's exclusive jurisdiction, sidelining state regulators.

But the judge said preventing states and Indian tribes from overseeing sports betting "upsets decades of federalism regarding gaming regulation, is contrary to Congress’ intent behind the (Commodity Exchange Act), and cannot be sustained."

Gordon also said the public interest supported letting Nevada regulate, because comprehensive regulation and strict licensing standards at the state level would protect consumers, including children and "problem" gamblers.

In similar cases this year, Kalshi prevailed in New Jersey but lost in Maryland. Both rulings were appealed.

Mike Dreitzer, chairman of the Nevada Gaming Control Board, said that body will vigorously oppose any effort by Kalshi to put Gordon's decision on hold during an appeal.

(Reporting by Jonathan Stempel in New York, Editing by Louise Heavens and Chris Reese)

((jon.stempel@thomsonreuters.com ; +1 646 223 6317; Reuters Messaging: jon.stempel.thomsonreuters.com@reuters.net /))