The uranium miner said Wednesday that the loss amounted to 37 cents per share for the quarter ended Sept. 30 compared with a profit of $211 million or 53 cents per share a year ago.
"Our results for the quarter reflect the ongoing challenges our industry is facing," Cameco president and chief executive Tim Gitzel said in a statement.
"But we continue to show that we're up for the near-term challenge as we prepare for the increased demand we see coming over the long term."
The biggest hit to the company's bottom line was a $184-million charge related to its investment in GE-Hitachi Global Laser Enrichment in North Carolina.
Cameco had warned in July that it might need to write down the investment after GLE's majority partner decided to reduce funding to the operation, which was being developed to process fuel for commercial nuclear reactors.
The company also took a $12-million charge related to its investment in GoviEx Uranium Inc.
Excluding the writedowns, the impact of foreign exchange and other one-time items, the Saskatoon-based company earned an adjusted profit of $93 million, or 23 cents per share, down from an adjusted profit of $208 million or 53 cents per share a year ago.
Analysts on average had expected a profit of 21 cents per share, according to Thomson Reuters.
However, revenue for the uranium producer totalled $587 million, down from $597 million a year ago. Analysts on average had expected $628 million, according to Thomson Reuters.
In its outlook, Cameco said it expected uranium production to come in at 22.6 million to 22.8 million pounds for the year, down from earlier expectations for 22.8 million to 23.3 million pounds.
The company also reduced its capital budget to $490 million, down from $550 million.
Cameco started producing uranium concentrate at the McClean Lake mill from ore mined at its Cigar Lake mine earlier this month.
Mining at the much-delayed Cigar Lake project began in March, but was suspended in July to allow the ore body to freeze more thoroughly.
Cigar Lake had faced years of delays due to massive underground flooding at the mine.