Regulators have shut small banks in Georgia and Michigan, bringing the number of bank failures this year to 117 amid the struggling economy and a cascade of defaults on loans.

The Federal Deposit Insurance Corp. on Friday took over United Security Bank, based in Sparta, Ga., with $157 million in assets and $150 million in deposits, and Home Federal Savings Bank in Detroit, with $14.9 million in assets and $12.8 million in deposits.

Ameris Bank, based in Moultrie, Ga., agreed to assume the assets and deposits of United Security, while Liberty Bank and Trust Co., based in New Orleans, is buying the assets and deposits of Home Federal Savings.

With United Security, 21 Georgia banks have failed this year, more than in any other state. Most of the failures have involved banks in the Atlanta area, where the collapse of the real estate market brought economic dislocation. Failures also have been especially concentrated in California and Illinois.

As the economy has soured, with unemployment rising, home prices tumbling and loan defaults soaring, bank failures have cascaded and sapped billions out of the federal deposit insurance fund. It has fallen into the red.

Depositors' money - insured up to $250,000 per account - is not at risk, with the FDIC backed by the government. The FDIC still has billions in loss reserves apart from the insurance fund. It can also tap a Treasury Department credit line of up to $500 billion.

Last week, regulators shut nine banks - including California National Bank of Los Angeles, the fourth-largest failure this year with $7.8 billion in assets and 68 branches - owned by holding company FBOP Corp. It was a new milestone: nine was the highest number of banks closed in a day since the financial crisis began taking down banks last year. Minneapolis-based US Bancorp bought the deposits and most of the assets of the banks, which included two others in California, three in Texas, two in Illinois and one in Arizona.