The business sentiment of South Korean firms improved for the second straight month in April, due primarily to seasonal effects.

According to the Bank of Korea on Tuesday, the April business survey index(BSI) for all industries came to 74, up one point from the previous month. 

A reading below 100 means pessimists outnumber optimists. 

The index, which posted an on-month increase of four points in March, marked the second consecutive rise this month.

South Korean manufacturers' business sentiment also increased two points to 75 this month, while the index for the non-manufacturing sector rose by one point, to 74.

The BSI outlook for all industries for next month rose one point to 77.