RICHMOND -- Mechanics Bank chief executive officer Steve Buster has decided to retire as the top boss of the community bank, which is more than a century old, to take a key role at a health care startup that he co-founded with his brother, the bank said Wednesday.

"The bank is really doing well this year, a lot of our non-performing loans have cleaned up, our profitability is moving along extremely well, we are very liquid and are well capitalized," Buster said in an interview with this newspaper. "If I am going to hand over the baton, it is a very good time to make a transition to a CEO without any burdens or liabilities in moving the bank forward."

Under Buster's leadership, Richmond-based Mechanics Bank has managed to churn out a string of profits, despite the devastation unleashed on numerous financial institutions during the recession.

"This has been a fascinating eight years," Buster said. "Everything was so good the first four years, and you have the challenges facing our industry that have been so big the last four years."

The bank also gained some notoriety during Buster's tenure when it refused to accept cash from the federal government under the U.S. Treasury Departments Troubled Asset Relief Program, also known as TARP. Bank officials said they didn't want a government bailout.

"Steve has always said he would see us thru the Great Recession," said Dianne Daiss "D.D." Felton," Chairman of the bank's board of directors. He has done so. We appreciate that he was able to do that."

During the third quarter that ended in September, the bank earned $7.8 million. That was 73 percent higher than the profits in the year-ago quarter.

Assets totaled $3.12 billion at the end of September, up 6.3 percent from the year before. Deposits totaled $2.64 billion, up 6.2 percent.

The bank also moved its administrative headquarters to Walnut Creek under Buster's leadership. The official corporate headquarters remain in Richmond.

Buster will become chairman of Previvo Genetics, a company he co-founded with his brother. Previvo Genetics is engaged in pre-implantation genetic diagnosis that can assure healthier children for couples with a high risk for genetic diseases.

"I have always wanted to exercise my entrepreneurial spirit," Buster said of his new role at Previvo. "If I don't do this now, I'm not going to do it. This will be real fun."

During the search for a successor, two executive vice presidents, Kirsten Weisser, who heads wealth management, and Richard Stephenson, chief legal officer and chief risk officer, will share the duties of president.

Despite his excitement about his new role with Previvo Genetics, Buster said he looks back with affection at his stint with Mechanics Bank.

"I have very mixed emotions leaving Mechanics Bank," Buster said. "I love this place. I love tis bank. I said it's the best bank in California and I mean it."

Contact George Avalos at 925-977-8477. Follow him at twitter.com/george_avalos.