L.A. investment bank B. Riley buys stock research firm Caris

B. Riley & Co., a Los Angeles investment bank, bought stock research firm Caris & Co. to increase its sales and trading business amid a slowdown in the brokerage industry.

B. Riley, founded in 1997, is adding nine analysts, 12 salesmen and four traders in San Francisco, New York, Los Angeles, San Diego and Atlanta, Chairman Bryant Riley said. Darren Caris, who was president of Caris & Co., will run research, sales and trading, the company said in a statement.

Small brokerages including ThinkEquity, Rodman & Renshaw and WJB Capital Group Inc. closed this year as institutional investors turned to computerized stock trading. Avian Securities shut down after failing to find a firm willing to take on its employees, founder Avi Cohen said last month.

“We’ve always expanded when it’s difficult,” said Riley, who declined to say how much he paid for Caris. “This will add to the research and sales side at a time when there’s less and less firms out there servicing the institutional investor.”

Caris specializes in providing advice on trading the stocks of technology and consumer companies, Riley said.