FirstEnergy Solutions filed for Chapter 11 bankruptcy Saturday evening.

The unregulated power generation arm of Akron’s FirstEnergy Corp. said in a 21-page document that it had more than $1 billion in liabilities and that reorganizing under the bankruptcy code was in the best interests of the company and creditors.

FirstEnergy Solutions was due to make a significant debt payment on Monday but did not have the funds on hand to make the payment.

The filing for bankruptcy protection includes FirstEnergy Solutions, along with all FES subsidiaries and FirstEnergy Nuclear Operating Co., according to a prepared statement released by FirstEnergy late Saturday night. The filing doesn’t involve FirstEnergy or its distribution, transmission, regulated generation and Allegheny Energy Supply subsidiaries.

“FirstEnergy and its other subsidiaries are not part of this Chapter 11 filing,” FirstEnergy President and CEO Charles E. Jones said in the prepared statement. “The six million customers of our regulated utilities will continue to receive the same reliable service, while our regulated generation facilities will continue normal operations, with the same longstanding commitment to safety and the environment.”

FirstEnergy had warned about the possibility since November 2016, with Jones telling analysts during a conference call that “competitive generation is weighing down the rest of the company” and noting that the odds were already stacking up against FES being able to service its debt on time.

FirstEnergy is continuing its previously announced strategy to exit the competitive generation business and become a fully regulated utility company.

Last week, the company confirmed it will move ahead with plans to retire four nuclear power plants for which it has been unable to attract a buyer.

“FirstEnergy will remain focused on creating long-term value for its customers, employees and shareholders,” Jones said. “Becoming a fully regulated utility company should give FirstEnergy a stronger balance sheet, solid cash flow and more predictable earnings. Simply put, we will be better positioned to deliver on the tremendous opportunities for customer-focused growth.”

FirstEnergy Solutions is owned entirely by FirstEnergy Corp.

FirstEnergy Solutions in turn owns FE Aircraft Leasing Corp., FirstEnergy Generation, FirstEnergy Generation Mansfield Unit 1 Corp., FirstEnergy Nuclear Generation LLC, FirstEnergy Nuclear Operating Company and Norton Energy Storage LLC.

The filing lists numerous creditors and shows FirstEnergy Solutions owes $769.2 million to Wilmington Savings Fund Society and hundreds of million dollars more to others.

Reporter Jim Mackinnon covers business and county government. He can be reached at 330-996-3544 or jmackinnon@thebeaconjournal.com. Follow him @JimMackinnonABJ on Twitter or www.facebook.com/JimMackinnonABJ