Sprint Nextel lost out in a bid to obtain AT&T documents that would have provided the third-largest U.S. wireless carrier with additional ammunition in its battle to stop AT&T's acquisition of T-Mobile USA.

Reuters reported that U.S. District Judge Ellen Huvelle denied Sprint's request for the documents, which would have also given the company valuable insight into rival AT&T's operations. Huvelle also heard arguments by AT&T seeking to dismiss lawsuits filed by Sprint and regional carrier C Spire in an attempt to block the T-Mobile deal. She has not yet made a decision on their standing as opponents of the merger.

AT&T's planned purchase of T-Mobile is under significant threat from the Justice Department, which has sued to block the deal. Sprint and C Spire have hopped on as well with their own lawsuits.

AT&T has said it is working on two tracks in an effort to salvage the deal, the first a possible settlement and the second the building of its court case.

Sprint, meanwhile, has argued that it should obtain documents that AT&T has provided to the Justice Department so it can adequately build its own case. Sprint also said AT&T already has the documents Sprint has given the Justice Department.

Reuters reported that Huvelle declined to give Sprint the documents. "I don't see it as efficient or fair," Huvelle said in denying the motion.

Sprint, for its part, called the denial of the documents and the review of its legal standing "procedural," saying they don't involve the merits of the case itself. The carrier argues that AT&T's potential acquisition of T-Mobile would stifle innovation and hurt consumers, as it would remove a low-cost provider of wireless service.