The nation’s third-largest wireless carrier, Sprint, has filed against AT&T in an attempt to block the $39 billion proposed acquisition of Bellevue-based T-Mobile.

Sprint’s suit will piggy back on the claim filed by the U.S. Department of Justice last week that argues the merger would increase prices and hurt competition in the wireless industry.

“Sprint opposes AT&T’s proposed takeover of T-Mobile,” said Susan Z. Haller, vice president-Litigation, Sprint. “With today’s legal action, we are continuing that advocacy on behalf of consumers and competition, and expect to contribute our expertise and resources in proving that the proposed transaction is illegal.”

Sprint argues that the merger would lead to a duopoly between AT&T and Verizon, currently the largest carrier, that would cripple competition for Sprint and smaller independent carriers.