The state-run Korea Development Institute (KDI) has offered a bleak diagnosis of the local economy for a fourth consecutive month.

The KDI said on Sunday in a monthly report that the Korean economy is exhibiting a slightly improved sluggishness in consumption but investments and exports have contracted, indicating that economic activities remain subdued.

The think tank used the term "slump" in its April report for the first time and has kept the diagnosis since. In the previous five months through March, it just said the economy was slowing.

The report said the country's exports fell 13-point-five percent on-year in June, led by semiconductors and petroleum products, and investments in facilities and construction remained depressed.

It said retail sales rose three-point-four percent on-year in May due mainly to the increased number of foreign tourists to South Korea.