Scania said it had a net loss of 150 million kronor ($ 19.7 million) for the three months to June, after a year-earlier net profit of 3.04 billion kronor.
Analysts had forecast a net profit of around 222 million kronor for the period after the company posted first quarter earnings of 179 million kronor.
Revenue fell 40 percent from a year earlier to 14.43 billion kronor.
“During the seasonally weak third quarter, Scania foresees a continued low level of demand,” it said.
Evli Bank analyst Michael Andersson told Dow Jones Newsires that analysts “maybe… were a bit too optimistic because of the good first quarter.”
“There’s still too many new trucks out in Europe,” he said. “For sure, there won’t be a European recovery this year. The question is what will happen next year? If there is a bounce back then I’m afraid it will be very small.”
Faced with the worst slump in years, Scania has cut costs like may automakers. In May, it introduced a four-day work week for about 12,000 employees in Sweden, reducing their pay by 10 percent.
It had some 32,600 employees at end-June, with nearly 4,000 having left the company since September 2008.