The head of RBC's U.S. wealth management unit will retire, a spokeswoman said.

John Taft, 61, had been CEO since 2005, and had overseen several acquisitions that have substantially grown the Canadian firm's U.S. brokerage business. The firm's most recent acquisition included City National, an elite Los Angeles-based bank that caters to Hollywood elites.

In a recent interview about that acquisition, Taft said it would boost his firm's banking and lending capabilities.

"When it comes to residential mortgages, personal lines of credits, credit cards -- City National has a private banking and commercial banking capability that will help us serve more of the needs of our clients than we have in the past. That's our long standing strategy of being the primary advisor to our clients," he says. "Our ambition is to do a better job of that than anyone else in this market."

RBC, which once had only a small footprint in the U.S., currently has about 1,900 financial advisors in 41 states and more than $270 billion in assets under administration. Measured by assets, RBC is the 7th largest brokerage in America, according to the firm.

Taft will be the most recent head of a major U.S. brokerage to exit the business.  Bob McCann, head of UBS Wealth Management Americas, stepped down in December. And just this week, Greg Fleming, president of Morgan Stanley Wealth Management, left the wirehouse after it was made clear that his path to the CEO position was blocked.

Taft's tenure not only included growth times; he also led the firm during the financial crisis of 2008 and 2009.

Taft joined RBC when the Canadian firm acquired the U.S. brokerage firm Dain Rauscher in 2000. He will step down May 31, according to the spokeswoman.

The firm is beginning a search for a successor.

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