In a move that will further the consolidation of fiber-based packaging suppliers, Smurfit-Stone Container Corp., the second-largest U.S. supplier of corrugated packaging and containerboard, has filed for Chapter 11 bankruptcy.

Smurfit-Stone’s bankruptcy filing, in late January, listed $5.6 billion in consolidated debt and $7.5 billion in consolidated assets as of Sept. 30. The bankruptcy filing is a reorganization rather than liquidation, meaning Smurfit-Stone will try to keep operating as it seeks to restructure its debt.

The Smurfit-Stone bankruptcy is the latest in a wave of mergers, acquisitions and closures that have concentrated fiber-based packaging in the hands of a shrinking group of suppliers. Other recent bankruptcies include Corp. Durango SAB, Mexico’s largest papermaker, and Pope & Talbot Inc., a Canadian pulp-mill operator.

If Smurfit-Stone drops from the scene, the choices of carton converters-and, by extension, carton users-will be constricted, says Mark Maley, vice president of sales for carton converter Caraustar.

“It’s fewer choices, and the choices are moving,” Maley says. “When you look in the rearview mirror, the choices were different, where you had a Field [Container Corp., acquired by Graphic Packaging in 2007] and you had a Smurfit. Now it’s all Graphic. So the choices are different, and there’s fewer of them.”