Bank of America Corp. has regained its spot as largest holder of deposits in the county after losing it to rival Wells Fargo & Co. last year.

Charlotte, N.C.-based Bank of America had $16.5 billion in local deposits as of June 30, according to the latest figures available from the Federal Deposit Insurance Corp.

BofA’s deposits were up 18%, or by $2.5 billion, from a year earlier.

The big gain helped BofA easily top Wells Fargo at $14.8 billion in local deposits as of June 30.

San Francisco-based Wells saw local deposits grow 5% from a year earlier.

Wells’ acquisition of Charlotte, N.C.-based Wachovia Corp., which closed in late 2008, helped it briefly overtake BofA.

Combining Wells’ deposits with Wachovia’s as of June 2008 when the deal was being finalized put Wells at $14.06 billion, just ahead of BofA at $14.03 billion.

BofA’s deposit gain in the past year came from consumers and businesses and no single event in particular, according to the company.

“Last year’s growth was blockbuster,” said Leigh Cross, regional executive for BofA’s consumer banking in Torrance. “Being the largest is very important to us.”

Part of the gain likely came from customers BofA picked up through its 2008 acquisition of mortgage lender Countrywide Financial Corp. of Calabasas, she said.

Banks have been looking to build deposits to bolster their books as they deal with bad loans and less demand for new lending.

BofA has seen trouble from bad mortgages from its buys of Countrywide and Merrill Lynch & Co. last year. The bank has taken $45 billion in federal bailout money.

In all, BofA has 22.5% of the market for deposits in the county, including about $300 million worth from First Republic Bank, which it acquired when it bought Merrill.