WASHINGTON (Reuters) -The U.S. antitrust enforcers greenlit T-Mobile's $4.4 billion acquisition of UScellular on Thursday, saying that while consolidation among cell carriers is concerning, UScellular customers would get more reliable service from the deal.

Gail Slater, head of the U.S. Department of Justice's antitrust division, said in a statement that the DOJ is closing its investigation without seeking to block the merger.

"UScellular's inability to maintain its competitive position would result in declining value to its subscriber base, whereas the transaction offers them hope that they will be able to experience the benefits of a more robust cellular network," Slater said in a statement.