TD Ameritrade Holding Corp.'s fiscal third-quarter earnings fell 2.3% as the online brokerage company's revenue and trading activity fell, company officials reported this morning.

For the quarter ended June 30, the Omaha-based firm posted a profit of $153.8 million, or 28 cents a share, compared with a year-earlier profit of $157.4 million, or 27 cents a share. It marked the second quarter in a row that the company's net income, coming on the heals of a 20.4% drop in second-quarter profits.

Net revenue fell 2.5% to $667 million after dropping 6.2% in the second quarter. Commissions and transactions fees declined 5.5% to $266.1 million.

Average daily client trades at Ameritrade totaled roughly 355,000 in the latest period, down from a year earlier, and down from the previous quarter.

Ameritrade officials said all brokerage companies are grappling with sluggish trading volumes amid the ongoing European sovereign-debt crisis and concerns about a slowing economy, while a flattening yield curve has pushed down margins.

"We're happy with our performance in the midst of what is a pretty difficult environment," said Fred Tomczyk, president and CEO of TD Ameritrade Holding Corp. "We've been through these environments before. The one thing we all know is that it won't last forever."

Added Tomczyk, "It does put pressure on all the players in the industry. However, I do hold the view that ... we're in the seventh inning of a nine inning ballgame. And it's one of those environments where everybody should be looking at all their options."

In an interview after the earnings call, Pete Dorsey, managing director of sales at TD Ameritrade Institutional, said that although market volatility has lessened, problems in China, India and Europe may still trouble investors

"It's definitely made the end clients, at least on the retail side, a little bit jittery and maybe a little bit less eager to engage in the trading volumes as they have in the past because of those macroeconomic issues," Dorsey said.

Despite the jittery market, Ameritrade reported continued asset growth. The company added $9.7 billion in net new assets in the latest quarter, compared with $7.9 billion a year earlier and $10.8 billion in the previous quarter. The company said it continues to be on pace for its fourth consecutive year of double-digit organic asset growth.

-Jim McConville