POSCO Holdings Inc., the holding firm of South Korea's top steelmaker POSCO, on Wednesday said that its third-quarter operating profit dropped 71 percent as some of its steel-processing facilities remain shuttered after a typhoon.

Its operating income stood at 900 billion won ($633 million) in the July-September period, compared with an operating profit of 3.1 trillion won a year earlier, the company said in a regulatory filing.

The operating profit was 17.8 percent lower than the average estimate, according to a survey by Yonhap Infomax, the financial data firm of Yonhap News Agency.

Sales rose 2.9 percent on-year to 21.2 trillion won. Net profit was not available.

In early September, POSCO was forced to halt three blast furnaces at its steel mill and steel processing facilities in Pohang, about 370 kilometers southeast of Seoul, as Typhoon Hinnamnor pounded some of its facilities.

The production of cold-rolled steel sheet and stainless steel was hardest hit by the powerful typhoon that killed more than 10 people, and left severe flooding and damage in its wake.

The steelmaker earlier expects 2.4 trillion won in lost revenue, some 2.7 percent of the steelmaker's annual revenue, with 170 tons of lost production.

The company will release its full earnings report later this month. (Yonhap)