(Adds market expectation)
RIO DE JANEIRO, Aug 6 (Reuters) - Brazilian steelmaker Usiminas on Thursday reported a loss for a fourth straight quarter amid with weak steel demand in a sluggish domestic economy and due to a writedown of iron ore mining assets of nearly a billion reais ($285 million).
Usinas Siderurgicas de Minas Gerais, as the company is known, reported a net loss of 781 million reais ($223 million) in the second quarter, after earning a net income of 129 million reais a year earlier, the last time it reported a profit.
The result widely missed the 76.4 million real average loss expected by four analysts surveyed by Thomson Reuters. Most of the survey was conducted before Usiminas on July 30 said it would delay results by a week to assess mining-related writedowns.
Belo Horizonte, Brazil-based Usiminas, the country's largest producer of flat-steel products used by the auto, shipbuilding and home appliance industries, has been hit by a sharp downturn in the world's seventh-largest economy.
"In the face of high stocks of goods, and consumer and business confidence indicators at historical lows, there are no signs of an imminent recovery," Usiminas said in a statement.
Industrial production fell 3.2 percent in June, compared to a year earlier, its 15th straight decline, after falling 8.9 percent in May.
While the intermediate-goods portion of industrial output, which includes steelmaking, fell only 1.7 percent in June, the production of durable goods, such as cars and home appliances, fell 2.4 percent, suggesting demand for steel may fall more in the near term.
Net sales, or total sales minus sales taxes, fell 14 percent to 2.68 billion reais.
Earnings before interest, taxes, depreciation and amortization, or EBITDA, was a negative 755 million reais compared with a positive 538 million reais a year earlier.
Usiminas results were dominated by an impairment of 985 million reais on its iron ore mining assets. The charge included a reduction in the value of mineral rights by 868 million reais at its iron ore mining subsidiary Mineração Usiminas SA and 117 million reais on rights owned by directly by Usiminas.
Some of the assets can no longer make money after the average iron ore price .IO62-CNI=SI fell 44 percent in the second quarter compared to a year earlier and 6.7 percent from the first quarter.
$1 = 3.499 Brazilian reais Reporting by Jeb Blount and Silvio Cascione; Editing by Lisa Von Ahn and Bernadette Baum