Hawaii Attorney General Clare Connors on Friday said the state has joined 13 other states in a lawsuit to halt the proposed merger of telecom giants T-Mobile and Sprint.

The complaint was originally filed on June 11 and amended on Friday.

Hawaii, Massachusetts, Minnesota and Nevada are now part of the original list of plaintiffs: New York, California, Colorado, Connecticut, Maryland, Michigan, Mississippi, Virginia, Wisconsin and the District of Columbia.

The complaint alleges that the merger of two of the four largest national mobile network operators would deprive consumers of the benefits of competition and drive up prices for cell phone services,” according to a press release from the Hawaii AG’s office.

Said Connors, “The proposed merger transaction raises significant antitrust concerns, which could adversely affect a consumer service that has become a necessary part of modern life.

T-Mobile US Inc. and Sprint Corporation are the third and fourth largest mobile wireless networks in the U.S., says the press release, “and are the lower-cost carriers among the ‘Big Four’ — Verizon Wireless and AT&T round out the market.”

It continues: “Intense competition, spurred in particular by T-Mobile and Sprint, has meant declining prices, increased coverage, and better quality for all mobile phone subscribers.