North Korea has demanded a $30 pay raise for its workers at an inter-Korean industrial complex in exchange for sending more workers, officials at South Korean companies operating in the complex said Wednesday.

The base pay of North Korean workers at the Gaeseong complex, named after the North's border city where it's located, was set at a minimum of $67 per month based on an inter-Korean agreement. South Korean companies give a 5 percent raise annually, and each company pays overtime.

"North Korean authorities demanded a raise in the base pay of Gaeseong workers by $30 on condition of additional deployment of North Korean workers to our plants," said an official at an association that represents South Korean companies at the complex.

The association members decided to draw up a unified stance in negotiating with the North on the matter, he said.

Some of the factory owners balked at Pyongyang's demand, expressing concerns that accepting it will lead to more demands for raises.

They say North Korea has consistently demanded pay raises whenever South Korean companies have asked for additional workers.

The Gaeseong Industrial Complex, an offshoot from an agreement from the first-ever inter-Korean summit in 2000, began operations in 2004. The complex now hosts some 120 South Korean companies that employ more than 44,600 North Korean workers. (Yonhap)