The result compared with a $500,000 net loss for the corresponding period last year.
The company wrote down the value of its 25% stake in Loy Yang, Victoria's largest power generator, by $65.1 million after determining that the carrying value of its investment exceeded the recoverable amount.
Horizon and its partners, US utilities NRG Energy Inc and CMS Energy Corp, are currently trying to sell the power station ahead of a $500 million bullet repayment of debt facilities due in May.
A syndicate made up of AGL and Tokyo Electric are considered favourites to win the bid after the withdraw of a rival Malaysian syndicate last week.
