NEW YORK (CNNMoney.com) -- Three regional banks were closed Friday, bringing the total number of failed banks this month to six, as the financial crisis continues to take a toll on small banks nationwide.

Suburban Federal Savings Bank in Crofton, Md., was closed by the Office of Thrift Supervision. The FDIC said the failed bank's seven offices will reopen on Saturday as branches of Tappahannock, Va.-based Bank of Essex.

The FDIC said it entered a "loss-share" agreement with Bank of Essex, whereby the purchasing bank will share some of the losses associated with certain of the failed bank's "asset pools." The arrangement is intended to maximize returns on the assets by keeping them in the private sector, according to the FDIC.

In Florida, the Office of the Comptroller of the Currency shuttered the four locations of Ocala National Bank and entered into a purchase agreement with CenterState Bank in Winter Haven, Fla.

Ocala National Bank had total assets of $223.5 million and total deposits of $205.2 million, while Suburban Federal had total assets of approximately $360 million and total deposits of $302 million.

Taken together, the two failures will cost the FDIC an estimated $225 million.

Separately, the FDIC said it was unable to find another financial institution to take over the banking operations of Salt Lake City-based MagnetBank, which regulators also closed on Friday. As a result, it expects to mail checks to retail depositors for their insured funds Monday morning.

MagnetBank, which is estimated to have no uninsured deposits, had total assets of $292.9 million and total deposits of $282.8 million as of last month, according to the FDIC. It was the first bank to fail in Utah since 2004.

The FDIC said it conducted "an extensive marketing process" to seek a buyer for MagnetBank's assets, but it found no takers.

David Barr, an FDIC spokesman, said MagnetBank had only one branch and did not have the "franchise value" or the "core assets" that would have made it attractive to other banks.

So far this year, bank failures are averaging more than one per week. Last year, 25 banks were closed nationwide, which was the highest annual total since 1993, when 42 banks went under.

Economists expect the number of failed banks to continue rising this year as the financial crisis plays out and the economic outlook remains dark.