SALT LAKE CITY—A Utah judge on Wednesday blocked TV streaming company Aereo Inc. from operating in several Western states, at least until the U.S. Supreme Court takes up a related case in April.

Broadcasters have argued Aereo is stealing TV signals without paying. Aereo says the tiny antennas it uses to capture signals before relaying them over the Internet should be treated the same as antennas that people use to pull TV signals for free.

District Judge Dale Kimball, who ruled Wednesday, argued that Aereo’s retransmission of video signals is “indistinguishable from a cable company.” He said that if Aereo continued to do business, it would damage broadcasters’ ability to negotiate with legitimate licensees, siphon viewers away from their websites and subject them to potential piracy.

Aereo charges upwards of $8 a month and offers its service in New York, Boston, Houston, Atlanta, and elsewhere. Subscribers get about two dozen local stations, plus the Bloomberg TV financial channel over computers, Internet-connected set-top boxes and mobile devices.

The U.S. Supreme Court, which will begin hearing arguments in the Aereo case on April 22, will aim to resolve different rulings in different districts. A ruling in the 2nd District Court of Appeals, which covers New York, Connecticut and Vermont, that said Aereo was not violating copyrights and allowed it to continue operating. Kimball’s ruling applies to the jurisdiction of the 10th District Court of Appeals, which covers Oklahoma, Kansas, New Mexico, Colorado, Wyoming, Utah and the parts of Yellowstone National Park that extend into Montana and Idaho.

Aereo launched service in all of Utah in August and in the Denver area in November. It hasn’t revealed how many subscribers it has.

Fox, the broadcaster owned by Twenty-First Century Fox Inc., said in a statement the ruling was a “significant win for both broadcasters and content owners.”

Aereo CEO Chet Kanojia said in a statement that he was “extremely disappointed” and will pursue “all available remedies” to restore service to the affected customers.