Aug 2 (Reuters) - For decades, bankruptcies have been rare in the $3.7 trillion municipal bond market, but experts say there now might be an uptick as counties, cities and towns work to recover from the economic recession while coping with stubbornly rising costs.

There have been nine Chapter 9 municipal bankruptcy filings so far this year, compared with 13 in all of 2011, according to James Spiotto, partner at Chapman and Cutler LLP.

Since 1980, there have been 271 muni bankruptcies, with most involving utilities and special districts, the data showed. Cities, villages and counties accounted for only 52 of the filings.

The highest number of bankruptcy filings occurred in Nebraska, followed by California and Texas.

Analysts, investors and traders are all watching to see what happens with a few possibly trailblazing cases still playing out.

SAN BERNARDINO, CALIFORNIA

San Bernardino filed for bankruptcy status on Aug. 1, becoming the third city in America's most populous state in recent weeks to use Chapter 9 in a fiscal crisis.

The city of about 210,000 residents located 65 miles (104 km) east of Los Angeles said it had more than $1 billion in debts, had tapped out its financial reserves, and had projected spending would top revenue by $45 million in the fiscal year that started on July 1.

MAMMOTH LAKES, CALIFORNIA

Mammoth Lakes went to federal bankruptcy court on July 3, seeking shelter from a $43 million legal judgment.

The resort town of about 8,000 in the Sierra Nevada Mountains filed for Chapter 9 bankruptcy after losing a legal battle with property developer Mammoth Lakes Land Acquisition. The company has said it would contest the town's eligibility for protection.

STOCKTON, CALIFORNIA

Stockton, a city of 300,000 located east of San Francisco, became the biggest U.S. city ever to file for bankruptcy in June, after years of fiscal mismanagement and a housing market crash left it unable to pay workers, pensioners and bondholders.

The filing followed months of confidential talks with creditors aimed at averting bankruptcy.

JEFFERSON COUNTY, ALABAMA

At $4.23 billion, Jefferson County set the record last November for the biggest municipal bankruptcy filing, which is still working its way through the court.

The county, home to Birmingham, Alabama's largest city, is saddled with massive sewer-system debt. A tentative workout, mainly with Wall Street creditors, unwound and scuttled concessions that might have been worth $1 billion to the county.

After the loss last year of a local jobs tax, the county has cut hundreds of staff, reduced services sharply and stopped payments on general obligation debt. Earlier this month, the county's computer systems failed, delaying payments of bills and deposits.

ORANGE COUNTY, CALIFORNIA

The county, California's third-most populous, filed for bankruptcy in December 1994 after rising interest rates savaged investment bets by its treasurer, leaving the county with a loss of $1.7 billion in an investment pool. That put Orange County at risk of a $1 billion default the next year.

Orange County emerged from bankruptcy after 18 months. It lost its title of the biggest municipal bankruptcy in U.S. history when Alabama's Jefferson County filed in November 2011.

HARRISBURG, PENNSYLVANIA

Harrisburg, the state capital of Pennsylvania, so far has lost in court when it has tried to file for bankruptcy. But it might relaunch that strategy when a state law banning its bankruptcy expires on Nov. 30.

With a population of 50,000, Harrisburg is plagued by $320 million of debt incurred by cost overruns from an upgrade of its incinerator.

On Tuesday, Harrisburg's City Council sued the state to halt work being done by a state receiver overseeing the city's fiscal recovery plan.

VALLEJO, CALIFORNIA

Vallejo, a former U.S. Navy town near San Francisco, filed for bankruptcy on May 23, 2008, after failing to address steep city personnel costs and sliding revenue from a housing slump.

In July 2011, the city won court approval for its financial plan to exit bankruptcy protection.

CENTRAL FALLS, RHODE ISLAND

The smallest city in the smallest U.S. state filed for bankruptcy on Aug. 1, 2011, after failing to win concessions from public-sector retirees and others to address an $80 million unfunded pension and retiree health benefit liability that was nearly quadruple its annual budget of $17 million.

Central Falls' bankruptcy was filed by its state-appointed receiver. The state has appointed budget commissions to oversee the finances of two other Rhode Island towns, East Providence and Woonsocket. 

(Reporting by Jim Christie, Verna Gates, Melinda Dickinson, Hilary Russ and Karen Pierog)

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