(REUTERS) -- U.S. wholesale baker Hostess Brands Inc filed for Chapter 11 bankruptcy protection in Manhattan on Wednesday, just months after emerging from a similar process last year, after failing to reach an agreement with workers on pension and health benefits.

Hostess was unable to reach an agreement with its unions regarding pensions, health and welfare benefits and work rule changes that ultimately led to insufficient liquidity, it said in court papers.

The company listed the Bakery & Confectionery Union & Industry International Pension Fund, to which it owes $944.2 million, as its largest unsecured creditor.

No one at the company could immediately be reached for comment.

The Twinkies and Wonder Bread baker listed assets of between $500 million and $1 billion and debts of more than $1 billion.

This is the second court restructuring for the Ripplewood Holdings-owned Hostess, which emerged from bankruptcy protection last September.

The case is Hostess Brands Inc, Case No. 12-22052, U.S. Bankruptcy Court, Southern District of New York (White Plains).

(Reporting by Kavyanjali Kaushik in Bangalore; Editing by Greg Mahlich)