Five senior employees of Brentwood-based RNC Capital Management have resigned and launched their own money-management firm, Oakwood Capital Management.

The group includes three of RNC’s six senior vice presidents: Nicanor Mamaril, who was RNC’s chief financial officer, Robert Blais, director of fixed-income investment, and Bruce Mandel, director of marketing.

Vice presidents Marla Harkness and Tom Doxey also left for Oakwood, as well as five other employees.

Since opening for business March 31, Century City-based Oakwood has seen its assets under management grow to around $100 million, according to Mandel, who is the new firm’s president and chief executive.

He says much of that business came from former RNC clients who have moved their accounts to Oakwood.

“It’s an amazing thing; when you are able to move key personnel, you find that clients are very receptive to moving with you,” he said.

RNC Chairman Daniel Genter confirmed that around $60 million in assets so far have been shifted from RNC to Oakwood. He said that the departures will only have a minor impact, since RNC’s director of equity research Jan Kallik and director of equity investment John Marshall will remain with his firm. RNC employs 50 people and has about $1.5 billion under management.

The departures came in the wake of a change of ownership at RNC. In March, Genter bought 100 percent of the company from former owner Bank of Austria for an undisclosed amount.

According to Mandel and other people close to RNC, the senior employees who left were uncomfortable with Genter’s expanded control of the money-management firm.

“When one person owns 100 percent, then nobody else has a vested interest and you have a lack of motivation among the other people in the company,” Mandel said.

Genter did not dispute that the ownership change was the catalyst for the exodus, but said the departures had more to do with his plan to reshuffle key employees after taking control.