US antitrust regulators urged a judge to give financially-strapped Dish Network Corp. more time to purchase airwaves from T-Mobile US Inc., which wants instead to auction the frequencies.

Dish should have until April 1 to buy the airwaves, after missing an August deadline for the $3.5 billion purchase, the Justice Department said in a filing late Monday at US District Court in Washington.

The support from the Justice Department help boost Dish’s stock 5% to $6.69 at 9:45 a.m. in New York trading Tuesday. The shares are down more than 50% this year.

The airwaves divestiture was ordered by US officials in an effort to restore competition lost when T-Mobile bought wireless provider Sprint Corp. in 2020.

T-Mobile earlier asked the court to deny Dish’s request so it can move to an auction. A handful of states taking part in the litigation surrounding the Sprint deal also opposed the extension, the department said in its filing.

Dish has agreed to waive any right to seek additional time, according to the filing.

“Dish is more likely to succeed as a national carrier if it obtains the 800 MHz spectrum that is the subject of the dispute,” the department said, referring to airwaves in the 800 megahertz band that are useful for mobile connections.

T-Mobile in the meantime can seek a buyer for the airwaves, the department said.

“T-Mobile will be free to conduct an auction and begin the process of seeking regulatory approval for the alternative buyer before April 1,” the department said in the filing.

Dish is merging with EchoStar Corp., a satellite communications company it previously owned, as a way to ease financial pressure and give it time to build a new wireless network. That still won’t resolve Chairman Charlie Ergen’s attempt to , but doesn’t solve Dish’s difficult transition to a mobile data service provider from a declining pay-TV network.

The case is US v Deutsche Telekom AG et al, 1:19-cv-02232, US District Court, District of Columbia (Washington, DC)

(Updates with stock price in third paragraph.)