Hundreds of municipalities in Ohio, along with the state’s governor and attorney general, are nearing an agreement on how to divide any money that might come from a major federal case against opioid manufacturers and distributors, an attempt to ensure fairness in the allocation of a potential settlement as recompense for the ravages of the nation’s opioid epidemic.

Cities and towns have until March 6 to sign onto the agreement, known as “One Ohio.” It would guarantee that the state presents a united front during negotiations, with municipalities directly receiving, in cash, 30 percent of any settlement funds. The state would receive 15 percent, and 55 percent would go toward a new nonprofit foundation that would support research into, and education about, opioids.

Thousands of municipalities and almost every state have sued companies that made and distributed opioid painkillers up and down the supply chain. Most of the cases are consolidated in a mammoth legal case based in Cleveland. Ohio is the first place to aim to have a team negotiate on behalf of the entire state to ensure equitable payments should there be a settlement before trial.

Four opioids — oxycodone, hydrocodone, heroin and fentanyl — have killed more than 400,000 people across the United States since the turn of the century, according to a Washington Post analysis. Ohio has been particularly hard-hit. In 2017, the state had the second-highest rate of opioid overdose deaths, according to the National Institute on Drug Abuse.

“Ohio is at the epicenter of the opioid crisis and still is fighting the addiction crisis with other drugs,” said Lisa Peterson, communications director for Gov. Mike DeWine (R). “By combining and presenting a united front, we think it will be beneficial for all areas of the state as we seek to get a settlement from these companies.”

State officials hope that the One Ohio framework, if adopted, can help provide a road map for other places that will need to allocate settlement money.

“Through this approach of providing funding and control locally, regionally and statewide, Ohio will have a unique tool for all of our communities to try to recover in a more expeditious and efficient manner,” said Frank L. Gallucci, a plaintiff’s attorney who represents 19 local governments in Ohio. “If successful in Ohio, it is our hope that this or a similar approach can be replicated for other states across the country.”

Cincinnati Mayor John Cranley (D) said he and other local government leaders are preparing to make a counteroffer to the plan. Cranley said he believes that municipalities should present a unified front but that the proposal put forward does not guarantee enough money for cities and towns.

“At the end of the day, people are dying in our communities,” he said, and those communities have had to bear an incalculable cost.

The push toward an agreement comes after more than 20 attorneys general signed a letter this month rejecting an $18 billion settlement deal proposed by three of the nation’s biggest opioid distributors.

Ohio’s action was spurred by a plan approved in June by U.S. District Judge Dan A. Polster, who is overseeing the case in Cleveland. To encourage a settlement, the plan increased the number of municipalities that are eligible for one. Polster has long said he wants to see a global settlement of all claims.

Two Ohio counties, Cuyahoga and Summit, reached a $260 million settlement with three opioid distributors and one drug manufacturer in October, averting an imminent trial. The counties also reached a $20.4 million settlement with Johnson & Johnson.

Cuyahoga and Summit counties are scheduled to go to trial in November against some of the nation’s largest pharmacy chains, including CVS, Walgreens and Rite-Aid.

The two Ohio counties are involved in what lawyers are calling “bellwether trials,” designed to help predict how other municipalities might fare should their cases settle or come before a jury.

Attorneys general have filed at least 89 opioid-related lawsuits against drug companies, and other entities have numerous lawsuits pending in state courts. Some attorneys general already have taken their cases to trial. Oklahoma Attorney General Mike Hunter (R) last year reached a $270 million settlement with Purdue Pharma, maker of the drug OxyContin, and an $85 million agreement with drug manufacturer Teva Pharmaceuticals. In August, a state judge ordered Johnson & Johnson to pay Oklahoma $465 million to remedy the effects of the opioid crisis.

In New York, the state and two counties on Long Island are scheduled to go to trial in March on their claims against numerous drug companies.

Lenny Bernstein contributed to this report.