March 6 (Bloomberg) --

Regulators shut banks in Maryland, Illinois, Florida and Utah, pushing the number of U.S. failures to 26 this year and placing more pressure on the Federal Deposit Insurance Corp. to dispose of a growing pile of toxic assets.

The FDIC was unable to find buyers for two banks -- Centennial Bank in Ogden, Utah, and Waterfield Bank of Germantown, Maryland -- according to statements posted on the agency’s Web site. In the largest of yesterday’s failures by assets, Boca Raton, Florida-based Sun American Bank was purchased by First-Citizens Bank & Trust Co.

“South Florida is a great market for our company, especially with our focus on individuals, small- to mid-sized businesses and the medical community,” Frank B. Holding Jr., chief executive officer of First-Citizens, said in a statement.

Lenders are collapsing at the fastest pace in 17 years amid losses on residential and commercial real estate loans made at the height of the market. U.S. “problem” banks climbed to the highest level since 1992 in the fourth quarter and FDIC Chairman Sheila Bair warned Feb. 23 that the pace of failures will “pick up” and exceed last year’s total of 140.