Yellow pages and Internet advertising firm Dex One and SuperMedia filed for bankruptcy protection as part of the companies’ merger plans.

Shareholders and lenders of Cary-based Dex One, formerly known as R.H. Donnelley Corp., and SuperMedia agreed to the prepackaged Chapter 11 bankruptcy plans, both companies said in separate petitions filed late yesterday and early today in U.S. Bankruptcy court in Delaware. The companies announced their merger plans last August. When complete, the combined company will be headquartered in Texas where SuperMedia is based.

In a prepared statement, the companies said they plan to to work with their respective exchanges to remain listed during the restructuring. Operations at both companies are expected to continue uninterrupted during the restructuring process. The restructuring is expected to be completed within 60 days. Dex One and SuperMedia said neither company would seek debtor-in-possession financing during the reorganization. The companies are seeking court authorization to continue paying vendors, suppliers and service providers in full under customary terms for all goods and services, including those provided before the filing date.

Dex One listed assets of $2.84 billion and liabilities of $2.79 billion. The company was known R.H. Donnelley before emerging from a bankruptcy reorganization in 2010. SuperMedia, which lists billionaire John Paulson’s Paulson & Co. as one of the shareholders, had assets of $1.4 billion and liabilities of $1.9 billion, according to its bankruptcy filing.

The merger will result in as much as $175 million in so- called yearly run rate savings by 2015, Dex One, said in its filing. Among Dex One’s largest unsecured creditors listed in court papers were holders of $219.7 million in senior subordinated notes with Bank of New York Mellon as trustee; and Google Inc., owed $11 million in trade debt.

Unsecured creditors cited by SuperMedia included Google, owed $3.74 million in trade debt; and Product Development Corp., owed $2.79 million.

(Bloomberg News contributed to this report)