Business sentiment for exports in South Korea fell to its lowest level in four decades, amid shock from the novel coronavirus pandemic.

According to the Korea Economic Research Institute(KERI) on Monday, the export portion of the business survey index(BSI) of the country's top 600 companies by sales came to 65 for May, the lowest since the think tank began the survey in 1980.

A reading below 100 means pessimists outnumber optimists, while a figure above the benchmark means the opposite.

The latest figure reflects a decline in overseas demand due to the outbreak affecting South Korea's major trading partners, including the United States, Japan and the European Union(EU).

The overall BSI for May stood at 61-point-eight, slightly up from 59-point-three a month earlier. 

In its analysis on April performances, the institute gave an index of 58-point-eight, the lowest since 58-point-one recorded during the global financial crisis in January 2009.