NEW YORK (AP) — Chesapeake Energy, a shale drilling pioneer that helped to turn the United States into a global energy powerhouse, has filed for bankruptcy protection.

The Oklahoma City-based company said Sunday that it was a necessary decision given its debt. Its debt load is currently nearing $9 billion. It has entered a plan with lenders to cut $7 billion of its debt and said it will continue to operate as usual during the bankruptcy process.

The oil and gas company was a leader in the fracking boom, using unconventional techniques to extract oil and gas from the ground, a method that has c...