Luminous Capital LLC, an independent wealth advisory firm started by a group of Merrill Lynch employees in 2008, is being sold to First Republic Investment Management Inc., a wholly owned subsidiary of First Republic Bank, the two firms announced Tuesday.

Luminous, based in Los Angeles and the Silicon Valley, has $5.5 billion in assets under management. It provides high-net-worth individuals, family offices and family foundations with investment advice and asset allocation.

The six partners of the firm will sign long-term employment contracts as part of the agreement, which is expected to be completed by the end of the year. The purchase price was not disclosed.

First Republic is a private bank with offices in California, Oregon, Massachusetts and New York.

"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 United States," says Luminous Capital CEO Eric Harrison.

Luminous Capital's origin was unusual in that it had been scheduled to become an office of Merrill Lynch when four of the future partners announced within an hour of its opening that it was becoming an independent wealth management firm.

Luminous took 14 Merrill Lynch employees with it and $1.7 billion in business. Less than three years later, the firm had $4 billion in assets under management, six partners and 21 employees.

-Karen DeMasters