Wells Fargo’s wealth, brokerage and retirement business’ fourth quarter revenue rose as the bank posted strong overall earnings for that quarter on Wednesday.

The firm’s wealth, brokerage and retirement business’ revenue rose 15% to $3 billion from a year earlier. Factors contributing to that gain included higher asset-based revenue, brokerage transaction revenue and net interest income. 

At the same time, Wells Fargo’s net income for that wealth, brokerage and retirement business was $197 million in the fourth quarter, up $213 million from a year earlier. That net income declined $59 million compared to the third quarter.

Wells Fargo’s investment management and trust asset-based revenue rose 6% from a year earlier.

The managed account assets under Wells Fargo’s retail brokerage business increased $38 billion, or by 20% from a year earlier. The firm attributed that gain to strong market gains and net flows.

Wells Fargo’s institutional retirement plan assets of $231 billion was also up from fourth quarter 2009 by 6%. Individual retirement account assets were at $266 billion in the fourth quarter of 2010, up 10% from a year earlier.

Those results come as the firm successfully completed the systems integration for its retail brokerage business over this past weekend, Wells Fargo CEO John Stumpf said on Wednesday’s earnings conference call. With that integration, the firm’s 15,000 advisors will work from one platform for trading, planning and investment activities.

“This further enables cross sell or cross banking [for] wealth management and brokerage customers nationwide,” Stumpf said of the integration. The firm plans to emphasize cross sell activities for that division, the firm said in the call.

“This business is an increasingly important business for us and an increasingly important source of cross sell,” Wells Fargo CFO Howard Atkins said of the firm’s wealth, management and retirement business.