A federal judge is allowing Sprint and C Spire Wireless' lawsuits against AT&T's merger with T-Mobile USA to proceed on the grounds that they could have an anticompetitive effect on the market for wireless devices.

"Sprint and Cellular South have adequately alleged a threatened antitrust injury with regard to the proposed acquisition's effects on their access to mobile wireless devices," Judge Ellen Huvelle wrote in a decision handed down Wednesday.

However, all but one of the operators' other claims were tossed out. The cases were also not given antitrust standing.

Judge Huvelle dismissed Sprint's claims over roaming, backhaul, spectrum and network development costs for lack of evidence.

She also dismissed C Spire's claims that the merger would impact roaming costs for its CDMA network, since AT&T and T-Mobile are both GSM-based, but allowed C Spire's claims about roaming costs for the small portion of its customers who use GSM service through its Corr Wireless subsidiary.

Sprint and C Spire remained optimistic about the case despite the mixed ruling. Both companies said Huvelle's decision to let the cases proceed on a limited basis would ensure they receive a "fair hearing."

AT&T general counsel Wayne Watts said he was "pleased" with the ruling. "We believe the limited, minor claims they have left are entirely without merit," he said.

The ruling could complicate AT&T's legal efforts over the T-Mobile acquisition. The operator is already facing a government antitrust suit over the merger from the Justice Department, which moved to block the deal in late August.