With all the turmoil in the finance industry in recent months, Donald Johnson, chief executive of L.A.-based American Business Bank, was hoping that his institution’s conservative lending and investment philosophy would result in some additional business.

But Johnson was still surprised by the surge in deposits at his bank over the last 90 days. They came as a result of people looking for safe havens after the collapse and federal takeover in July of IndyMac Bank.

“In a normal month, we get about $6 million in new deposits. Since June, we’ve been averaging about $25 million per month,” Johnson said. “We’ve also doubled the number of depositors. It’s turned out to be an embarrassment of riches.”

American Business Bank is not alone.

At Beverly Hills-based City National Corp., parent of the largest bank headquartered in L.A. County, deposits in July hit $335 million, four times the historical July average. “We’ve definitely seen a flight to safety, which started with the rumors about Bear Stearns and picked up steam with the IndyMac situation,” Chief Executive Russell Goldsmith said. He noted that City National never made subprime loans, did not purchase brokered mortgages and has remained profitable.

And Bank of America, the Charlotte, N.C.-based behemoth, has also seen a deposit surge in many of its local branches, though spokeswoman Brittany Sheehan attributed at least part of the spike to a long-planned marketing campaign that coincidentally aired in July, after the IndyMac debacle.

Federal regulators seized Pasadena-based IndyMac on July 11, after depositors withdrew more than $1 billion in what was described as a run on the bank after reports surfaced of mounting mortgage losses.

City National’s Goldsmith said the surge in deposits that followed the IndyMac takeover went across most of its client base, which consists of entrepreneurs, corporations, professionals and executives. Most depositors were trying to find the safest locations for their money.

Johnson, though, said most of the new deposits came from prospective business clients.

“We have for years tried to lure business customers from other banks,” he said. “But the typical response had been one of inertia: People were staying with their banks.”

That has changed.

“People who had previously only thought about moving to us actually took the plunge and made the move,” he said.