GILLETTE, Wyo. – The nation’s third-largest coal company by production volume filed for bankruptcy Friday as utility companies increasingly turn to gas-fired generation and renewable energy for electricity.

Gillette-based Cloud Peak Energy filed for Chapter 11 reorganization in U.S. Bankruptcy Court in Delaware. The move was widely expected since at least March, when the company received the first of several extensions to make a $1.8 million loan payment.

The latest extension expired Friday.

Cloud Peak owns and operates three mines in the Powder River Basin: the Antelope and Cordero Rojo mines in Wyoming and the Spring Creek Mine in Montana.

The mines shipped 50 million tons of coal in 2018. Cloud Peak officials say the mines will remain in operation during the bankruptcy process.