State regulators closed six banks in Illinois and one in Texas, raising the number of bank failures in the U.S. to 52 this year. The seizures were the most in a single day during the financial crisis.

The Federal Deposit Insurance Corp. said the closures of First State Bank of Winchester, John Warner Bank, Rock River Bank, Elizabeth State Bank, First National Bank of Danville, Founders Bank and Millennium State Bank of Texas are estimated to cost the FDIC $314.3 million. Founders Bank was near Chicago, but the rest were spread around the state. Thursday's failures give Illinois 12 seizures for 2009, surpassing Georgia for most closures among U.S. states.

A real-estate slump and souring construction and development loans help explain some of the banking woes in Illinois. One other factor is the number of financial institutions: Illinois is home to 650 banks, more than in any other U.S. state.

The largest to go down Thursday was Founders, located south of Chicago in Worth, Ill. The FDIC sold Founders Bank's $848.9 million in deposits to PrivateBank and Trust Company of Chicago. PrivateBank also took $888.4 million of $962.5 million in assets and agreed to share losses on $617 million.

The smallest failure was Winchester, Ill.-based First State Bank, which had assets of $36 million and deposits of $34 million as of April 30. First National Bank of Beardstown, of Beardstown, Ill., agreed to buy the bank's deposits and $33 million in assets. The FDIC will share losses on $20 million in assets.

Elsewhere, State Bank of Lincoln, of Lincoln, Ill., agreed to assume the $64 million in deposits held by John Warner Bank, of Clinton, Ill., as well as $63 million of the seized bank's $70 million in assets. The FDIC will hold the remaining assets for sale at a later date. The agency and State Bank of Lincoln will share the losses on $31 million of assets.

Harvard State Bank of Harvard, Ill. agreed to buy Oregon, Ill.-based Rock River's $75.8 million in deposits and assume $72.9 million of $77 million in assets. The FDIC and Harvard will share losses on $51.3 million in assets. Terre Haute, Ind.-based First Financial Bank bought $147 million in deposits from First National Bank of Danville, Ill. It also assumed $148 million of its $166 million in assets and agreed to share losses with the FDIC on $97 million of those assets. The FDIC sold Elizabeth State Bank's $50.4 million in deposits to Galena State Bank and Trust of Galena, Ill. Galena also purchased $52.3 million of $55.5 million in assets and agreed to share losses on $44.5 million.

The Texas failure was in Dallas, where the FDIC sold Millennium State Bank of Texas' $115 million in deposits to State Bank of Texas in Irving, Texas. State Bank also purchased all $118 million in assets.