The operating ratio of South Korea's semiconductor industry fell to a 43-month low in February amid a sharp drop in chip exports.

According to tentative data by Statistics Korea on Sunday, the operating ratio of the industry stood at 97-point-one last month, down four percent from a month earlier.

This is the lowest reading since July 2015 when it marked 91.

The index, which uses 2015 as a reference point of 100, has slipped for four straight months, after reaching a high of 114-point-one in October of last year.

Last month's tally also marks the first time the index fell below the 100 mark after 98-point-two was reported for August 2015.