Banks insured by the Federal Deposit Insurance Corp. saw their deposits rise in 2012 even as they cut back on the number of offices operating across the U.S.

The amount of insured deposits in 2012 experienced the largest one-year percentage increase in six years last year, the financial regulator noted in its summary of deposits report.

Additionally, the institution said total domestic deposits increased 8.5% for the year ending June 30,2012, the largest one-year percentage increase in domestic deposits over a six-year period.

However, the total number of offices operated by FDIC-insured institutions continued to drop, falling 1% or by 857 offices, to just under 97,000 locations.

"Contraction in the number of offices largely reflects the continuing decline in the number of FDIC-insured institutions," the FDIC said.

The number of offices held open by FDIC-insured institutions fell by 267 units, compared to 317 the previous year.

As a whole, all geographic areas reported deposit growth and office contraction from 2011 to 2012, but deposits held in metropolitan areas were the strongest, growing 9.1% in 2012.

"If you step back from it and look year over year, the branches are down, the customer satisfaction is up, and the deposits are up strongly, which is a nice combination," said Brian Moynihan, president and CEO of Bank of America (BAC), in the company's first-quarter earnings address.

For months, market analysts have noted that some banks are focusing on more tailored, smaller retail branches while others are closing excess branches as the market.