The states of New York, California, Washington, Illinois, Massachusetts, Ohio and Pennsylvania have joined the DOJ's antitrust lawsuit against AT&T, T-Mobile USA and T-Mobile parent Deutsche Telekom, the DOJ said Friday.

The deal, which would create the largest mobile carrier in the U.S., would significantly reduce competition, jack up prices and stifle innovation, the , filed Aug. 31. The DOJ pointed to T-Mobile USA's role as a low-cost competitor to the three other nationwide mobile carriers as a reason to block the deal.

AT&T officials have said they will fight the lawsuit. The company has argued the merger will allow it build out mobile broadband service to more U.S. residents and will help it improve quality of service.

The company continues to seek an expedited hearing on the DOJ's complaint, an AT&T spokeswoman said. "On a parallel path, we have been and remain interested in a solution that addresses the DOJ's issues with the T-Mobile merger," she said.

It is "not unusual" for state attorneys general to participate in DOJ merger reviews, the spokeswoman added. "At the same time, we appreciate that 11 state attorneys general and hundreds of other local, state and federal officials are publicly supportive of our merger," she said.