In the past, upon facing financial trouble, United Continental Holdings Inc's (UAL.N) United Airlines and Delta Air Lines Inc (DAL.N) have taken the Chapter 11 route to cut costs and later found merger partners. AMR Corp, the parent of American Airlines, had also filed for bankruptcy late last year.

In a filing with a U.S. bankruptcy court, Pinnacle said it seeks to resolve its operational and financial difficulties through the Chapter 11 process. It also seeks to implement a turnaround plan by cutting costs and restructuring certain agreements with major airlines.

Pinnacle is a regional airline headquartered in Memphis, Tennessee that provides transportation between hubs and smaller outlying cities for passengers ticketed by major carriers.

At present, Pinnacle's primary customer is Delta Air Lines, with additional flying currently provided to United Airlines and, to a much lesser extent, US Airways.

In light of high fuel costs and weak travel demand, Pinnacle said major carriers have aggressively cut costs and decreased capacity.

"The result has been a race to the bottom, as the debtors and other regional airlines have been forced to bid ever-lower rates and accept increasingly unfavorable contract terms to win the business of major carriers," Pinnacle said in the filing.

The regional airline said it had received a commitment for $74.3 million of debtor-in-possession (DIP) financing from Delta Air Lines that would help it to carry out normal operations.

As part of the bankruptcy plan, Pinnacle said it would restructure its key operating agreements with Delta Air Lines and would wind down its operations with United Airlines.

The company said it would also look to achieve workforce cost savings by seeking wage reductions and other concessions from labor unions. The airline said it hopes that consensual agreements can be reached with the unions.

However, there is a possibility that Pinnacle could face turbulence from the unions on the question of wage cuts, which could potentially result in a protracted court battle.

In November, AMR Corp, the parent of American Airlines, filed for bankruptcy and immediately flew into trouble with unions over negotiation of labor contracts.

In March, AMR sought bankruptcy court approval to throw out labor contracts, a move that puts new pressure on pilots, flight attendants and other unionized workers to quickly agree to concessions.

Pinnacle had listed estimated assets and liabilities above $1 billion, according to a court filing.

The case is Pinnacle Airlines Corp, Case No. 12-11343, U.S. Bankruptcy Court, Southern District of New York.

(Reporting by Sakthi Prasad; Editing by Michael Perry and Jeremy Laurence)

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