FACTBOX: Recent and major U.S. municipal bankruptcies

CHICAGO (Reuters) - Alabama's governor and Wall Street lenders are working to avoid a municipal bankruptcy filing by Jefferson County stemming from problems associated with the county's $3.2 billion of sewer debt. An agreement reached on Friday that extends until September 30 will keep some of the debt from defaulting.

U.S. municipal bankruptcies are rare, with fewer than 600 Chapter 9 filings since 1934, when the first municipal bankruptcy law was passed, according to a June presentation by the law firm Mintz Levin. A bankruptcy filing by Jefferson County could be the largest Chapter 9 filing, depending on the amount of the county's defaulted debt. The following are the largest or most recent filings and their triggers:

-- Washington Public Power Supply System filed for bankruptcy protection in 1983 after defaulting on $2.25 billion of bonds

-- Orange County, California, filed for bankruptcy protection in 1994 in the wake of losing $1.6 billion from its investment pool due to interest rate derivatives

-- Vallejo, California, filed for bankruptcy protection in May 2008, citing overwhelming payroll expenses and sliding revenue, as well as liabilities of up to $500 million.

Source: Reuters reports

(Reporting by Karen Pierog; Editing by Dan Grebler)