A Cowen & Co. analyst predicts that states opposing T-Mobile US Inc.’s $26.5 billion takeover of Sprint Corp. may have convinced a federal judge to block the deal.

Based on two weeks of court testimony last month and the nature of the questions U.S. District Judge Victor Marrero asked during the proceedings, analyst Paul Gallant sees a 60 percent chance the ruling will favor the state attorneys general, according to a note Thursday.

The case will help determine the fate of the U.S. wireless industry as the two smaller national carriers seek to combine into a more effective competitor to Verizon Communications Inc. and AT&T Inc. Democratic attorneys general from 13 states and the District of Columbia are fighting to block the deal, saying the combination would harm consumers through higher prices and weaker service.

The pivotal question is whether the combination of T-Mobile and Sprint would simply shrink the playing field to three national carriers, or if, under a plan approved by U.S. regulators, Dish Network Corp. would set up an effective new wireless carrier with assets bought from Sprint and T-Mobile. The Justice Department and the Federal Communications Commission have already OK’d the deal.

The attorneys general may have successfully framed the issue as too much industry concentration, said Gallant, a former legal adviser to the FCC. “Both the parties’ private texts and Marrero’s own questions repeatedly referred to this as a ‘four to three merger,’ ” Gallant wrote. If so, that “probably met their initial burden of proof.”

The companies have tried to address the concerns about higher prices. To win approval of the merger, T-Mobile has pledged to freeze prices for three years, offer free wireless broadband access to 10 million underserved students and roll out a new $15-a-month data plan capped at 2 gigabytes.

It’s not clear if Judge Marrero views consolidation as necessarily translating to higher prices, and he expressed doubts about unilateral price increases.

Carl Shapiro, an economics professor at the University of California at Berkeley, testified as an expert witness for the states, saying the merger would cost consumers as much as $8.7 billion more. After his testimony, Marrero asked him if the wireless companies would “be so bold” as to raise prices after the merger without also offering better services.

Closing arguments are expected later this month, and a ruling could come as early as February.