Hawaii, Massachusetts, Minnesota and Nevada are joining the legal fight against T-Mobile's $26.5 billion bid for Sprint in a case that may reach trial in October.

A lawyer for state attorneys general revealed the additional states at a New York court hearing Friday.

Nine other states and the District of Columbia sued to block the merger this month, saying it will reduce competition and damage consumers.

A lawyer for T-Mobile told a judge Friday that the deal will improve competition by combining two smaller companies, enabling them to compete more effectively against bigger players.

Both sides recommended an Oct. 7 trial date.

U.S. District Judge Victor Marrero did not agree to the date yet, saying any trial date will depend in part on whether the Justice Department joins the states.

“Protecting Nevada’s consumers is one of my top priorities,” said Nevada Attorney General Aaron Ford. “Our office is exploring all options to ensure that this merger would not negatively affect Nevada families, businesses and workers.”

The amended complaint includes the states of New York, California, Colorado, Connecticut, Hawaii, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Nevada, Virginia, Wisconsin, and the District of Columbia.

The state AGs say the merger would hurt competition and drive up prices for cellphone service.

It's an unusual step ahead of a decision by federal antitrust authorities. The Justice Department's decision is pending. The Republican majority of the Federal Communications Commission supports the deal.

The companies say they need to bulk up to upgrade to a fast, powerful "5G" mobile network that competes with Verizon and AT&T. The companies are appealing to President Donald Trump's desire for the U.S. to "win" a global 5G race.

Consumer advocates and Democratic lawmakers worry about price increases and job cuts. (AP)