The state-run power company is selling the land, a highly coveted property that, according to KEPCO, is estimated to be worth 3.33 trillion won (US3.3 billion), to reduce its debts.
The move comes as KEPCO is set to relocate its main office to Naju, a city in South Jeolla Province, in November.
Potential buyers include two South Korean conglomerates - Hyundai Motor and Samsung groups. The former has expressed its determination to buy the land to build a business complex, while the latter has yet to clarify its stance on the matter.
Possible foreign participants in the bidding include Chinese property developer Greenland Group and U.S. casino and resort company Las Vegas Sands Corp. Foreigners can submit a bid only by joining a local consortium.
The government has ordered debt-ridden public firms to take measures to reduce their huge debt on their own.
The bidding will close on Sept. 17, according to KEPCO.