San Francisco's First Republic Bank is to acquire Los Angeles, CA-based Luminous Capital, an independent high net worth wealth advisory firm with $5.5 billion in wealth management assets, for an undisclosed cash sum.

According to a statement, Luminous' six partners will sign long-term employment contracts as part of the transaction, which is expected to close by December 31, subject to customary conditions.

“Luminous Capital is a perfect fit with First Republic, and we welcome the opportunity to work with a team of wealth managers and bankers who have such a stellar reputation,” said Luminous chief executive Eric Harrison. “Luminous Capital clients will have full access to the substantial resources and capabilities of First Republic, one of the strongest and most client-centric private banks in the US.”

"Luminous aligns with and will complement our existing wealth management capabilities," added First Republic's CEO and chairman, Jim Herbert.

Luminous serves individuals, family offices, and family foundations with investment advice and asset allocation, including alternative investments. It operates in the same markets and segments as First Republic Investment Management, with offices in Portola Valley on the San Francisco Peninsula and in Century City. The firm’s founding partners previously helped grow wealth advisory businesses at both Goldman Sachs and Merrill Lynch.

Last month First Republic reported that wealth management assets at the New York-listed firm stood at $24.8 billion at September 30, up 7 per cent for the quarter and 22 per cent since year-end. For the group, net income for the quarter was $102.7 million, compared to $87.8 million for the third quarter of 2011, up 17 per cent.