Ameriprise Financial Inc. said it plans to sell independent broker-dealer subsidiary Securities America Inc., as its net income rose to $241 million for the first quarter over $214 million in the previous year.

Ameriprise’s positive first quarter results were tempered by a $77 million after-tax charge from legal expenses at Securities America. Ameriprise plans to find a buyer for that business, it said in the earnings report on Monday, as Ameriprise plans to focus more on its own advisor business.

 Securities America and its holding company Securities America Financial Corp. have recently wrestled with litigation related to the scrutinized sale of private placement securities. On April 15, Securities America entered into settlement agreements including a $118 million pre-tax charge in the first quarter for private placements sold by Medical Capital and Provident Royalties. Those charges came after Securities America also had a $40 million pre-tax charge related to the private placements in the fourth quarter. Both Medical Capital and Provident Royalties are the subject of fraud charges from the Securities and Exchange Commission.

“We appreciate the many years Ameriprise has committed to our independent business model,” Securities America Spokeswoman Janine Wertheim said in a statement in response to the announcement of the sale plans. “Their willingness to provide the financial means for the Medical Capital and Provident Royalties settlement leaves Securities America in a strong financial position to continue operations with no disruptions. We believe there are many options that will afford enhanced opportunities and benefits to our advisors and employees. Our record first quarter results make this an opportune time for an ownership change.”

Ameriprise began reporting Securities America’s results with its corporate and other segment results starting this quarter. That division had a pretax loss of $197 million. Its segment operating loss increased to $181 million for the quarter compared to $27 million for the previous year. The $154 million increase was mostly due to Securities America’s legal expenses, the firm said.

Excluding those legal costs, Ameriprise’s operating earnings rose 54% to $347 million for the first quarter compared to $226 million for the same period in 2010. The firm said that growth was due to strong results in its asset management and advice and wealth management businesses.

Ameriprise’s operating net revenue lifted 22% to $2.6 billion for the first quarter compared to $2.1 billion in the previous year. That growth was due to the acquisition of Columbia Management, a transaction that took place one year ago and ushered in more asset-based fees, as well as increased retail client net inflows and market appreciation.

Ameriprise’s assets under management and administration rose to $693 billion for the first quarter, a 50% increase from the same quarter in 2010.

Ameriprise had more than $1.5 billion in excess capital as of March 31 after using $395 million to repurchase 6.5 million shares of stock. Ameriprise also has about $531 million left from a May 2010 authorization to repurchase stock shares.

The advice and wealth management business’ total branded retail client assets increased by 13% from the first quarter of 2010 to $315 billion as market appreciation and retail client net inflows rose. Advice and wealth management had pretax income of $100 million for the first quarter. Segment operating earnings rose to $99 million from $51 million in the first quarter of 2010.

Advisor productivity reached “record levels” in the first quarter, Ameriprise Chairman and Chief Executive Jim Cracchiolo said in a statement. That included a 23% increase in operating net revenue per advisor from the previous year, amounting to $95,000 per advisor for the first quarter, as client activity and assets under management picked up.

The number of advisors under the Ameriprise brand fell 3% compared with the same period last year as the firm has cut ties with low-producing advisors and focused on hiring and retaining higher producers.

Ameriprise’s asset management business had pretax income of $107 million in the first quarter, while its segment operating earnings increased to $136 million from $22 million for the first quarter of 2010. The firm’s annuities business had $154 million in pretax income in the first quarter, while segment operating earnings grew $40 million from Q1 2010 to $174 million.