State regulators closed seven banks in on Thursday raising the total number of failed banks to 52 this year.

Six banks were shuttered in Illinois and one in Texas, the seizures were the most in a single day during the financial crisis.

The seven lenders seized yesterday, with total assets of $1.49 billion and deposits of $1.34 billion, were closed by state or federal regulators and the Federal Deposit Insurance Corp. was named receiver, according to statements from the FDIC. Buyers were named for each of the closed institutions.

Illinois leads the number of banks failed with a total of 12 closed banks.

The six failed Illinois banks are all controlled by one family and followed a similar business model that created concentrated exposure in each institution, the FDIC said. CDOs, which packaged bonds and loans into notes of varying risk and yield, lost money as real estate defaults soared.

According to FDIC estimates, yesterday's seizures will cost its insurance fund $314.3 million. The regulator imposed an emergency fee in May to raise $5.6 billion to rebuild the fund, which has deteriorated in the past 18 months.