Yellow pages and Internet advertising firm Dex One, formerly known as R.H. Donnelley, and SuperMedia filed for bankruptcy protection in the U.S. Bankruptcy court in Delaware as part of the companies’ merger plans.

The companies said shareholders and lenders agreed to the prepackaged Chapter 11 bankruptcy plans. Both companies said neither would seek debtor-in-possession financing during the reorganization.

The companies announced their merger plans last August. When complete, the combined company will be headquartered in Texas where SuperMedia is based.