Kansas City, Mo ? Aquila Inc. announced Thursday that it lost $810 million during the second quarter, largely due to one-time charges from its investment in Quanta Services Inc. and the scaling back of its wholesale energy trading business.

The losses of $5.69 per share for the quarter that ended June 30 compared with earnings of $143.2 million, or $1.21 per share, during the same period last year.

Excluding one-time charges, second quarter operating earnings were 34 cents per share. Analysts surveyed by Thomson First Call had predicted earnings of 16 cents per share.

Kansas City-based Aquila also reduced its earnings guidance for the year to $1 per share, down from $1.30 to $1.40, because of lower than expected power prices, reduced liquidity in the energy market and an oversupply of electric generation capacity, said Robert K. Green, president and chief executive officer.

Shares of Aquila closed down $1.05 at $4.95 in trading Thursday on the New York Stock Exchange.