Bank of America’s wealth management business, which includes the Merrill Lynch brokerage division and U.S. Trust, posted solid gains in both revenue and income for the fourth quarter, capping what CEO Brian Moynihan called the division's "best year in the company’s history.”

The unit posted revenue of $4.5 billion for the fourth quarter, up seven percent from the same time frame last year, and earned $777 million, a 35 percent increase, largely driven by market gains and positive long-term asset flows. For the year, the unit's revenues were $17.8 billion, a 7.7 percent increase over 2012. Merrill Lynch and U.S. Trust earned a record $3 billion in profits, up 33 percent over 2012.

Assets under management at the division increased 18 percent to $821 billion, while brokerage assets were up 8.8 percent to $1 trillion. Merrill Lynch made $1.8 billion on asset management fees, up 15 percent over last year. Total client balances were up 10 percent to $2.37 trillion.

Advisor headcount within the Merrill Lynch unit fell. Merrill lost 268 advisors during the quarter, ending with 13,771. The "thundering herd" of advisors stood at 14,915 one year ago. 

The company attributed the decline to the continued attrition of underperforming advisors within Merrill’s training program.  Two-thirds of advisor losses were from the bottom quadrant of trainees, the firm reported, with competitive losses down 50 percent in 2013 year-over-year. With more assets and fewer advisors, advisor productivity increased 11 percent, from $900 to $1 billion. A Merrill spokesperson says not including advisors in the training program, advisor productivity increased to $1.3 billion. 

Overall, Bank of America overall posted revenues of $21.7 billion in the quarter, up 15 percent year over year, with earnings jumping 35 percent to $3.4 billion.