South Korean firms say they've had systemic and other difficulties in inter-Korean economic cooperation projects.

They assessed the North as a less attractive investment option than China or Vietnam.

The Korea Chamber of Commerce and Industry surveyed 200 companies participating in joint business projects and 300 other firms among the top thousand in terms of sales.

The survey found that 80 percent of inter-Korean project participants were having or had experienced regulatory and procedural difficulties.

Almost half noted transit, communications and customs problems. They also cited the lack of a dispute settlement system and obstacles to financial transactions.