Production at the Kaesong estate has been suspended since North Korea withdrew its 53,000 workers from the complex in April at the height of soaring military tensions with the South.
Working-level officials from both sides have already met four times this month to discuss the future of the complex, established in 2004 as a rare symbol of inter-Korean cooperation.
The talks have been dominated by mutual recrimination over the cause of the shutdown, and the unwillingness of either side to be seen to make any concession to get Kaesong running again.
"We will try our best to produce results that are acceptable to South Korean people," Kim Ki-Woong, the chief of the South's three-member delegation, said before crossing the border.
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The South is insisting North Korea provide guarantees to prevent any repetition of what Seoul insists was the unilateral closure of Kaesong by Pyongyang.
The North says it was not responsible, arguing that its hand was forced by hostile South Korean actions and intimidation -- in particular a series of joint military exercises with the United States.
The South has proposed allowing foreign firms to operate there in the apparent belief that it would make it more difficult for the North to shut down the complex at will.
North Korea wants an unconditional and early restart of operations, and both sides have accused the other of lacking sincerity in the negotiating process.
South Korean President Park Geun-Hye urged the North to learn from other communist nations that have benefited by reforming their economies and adopting global codes of practise.
"I hope that the latest talks will produce meaningful and sustainable agreement," she added.
Born out of the "Sunshine Policy" of inter-Korean conciliation initiated in the late 1990s by South Korean president Kim Dae-Jung, Kaesong was a crucial hard currency source for the impoverished North through taxes, revenues, and its cut of worker wages.