Kansas City, Mo. ? Aquila Inc. said Wednesday it lost $331.6 million in the third quarter, partially because of costs associated with exiting its energy-trading business.

The losses of $1.85 per share for the period ending Sept. 30 compared with earnings of $68.9 million, or 58 cents per share, during the same period last year.

The company also announced Tuesday plans to indefinitely suspend its quarterly cash dividend, a decision aimed at improving its credit.

Excluding one-time charges of $226 million :quot; $70.8 million from the company’s efforts to exit the energy-trading business :quot; Aquila’s third-quarter operating loss was 14 cents per share. That was in line with the estimate of analysts surveyed by Thomson First Call.

Sales in the quarter fell 28 percent to $576.5 million, down from $804 million in the same period last year.

“The third quarter and the year as a whole have been a disaster for Aquila as well as for our industry,” said Richard C. Green Jr., chairman, president and chief executive officer.

“Exiting the wholesale energy trading business, writing down assets, reducing the work force by approximately 1,600 employees, cutting and then suspending the dividend all have caused our shareholders and employees a great deal of pain.”

Shares of Aquila fell 5 cents on Wednesday to close at $3.34 on the New York Stock Exchange. They plunged 22 percent in extended trading, after the market closed and the earnings were released.