The park, costing a total $2.5 billion, will be jointly developed by the Haitian government, the US government and the Inter-American Development Bank (IADB) -- part of efforts to help the island recover from last year's devastating earthquake.
Sae-A Trading currently produces clothes for big-name outlets including Walmart, Target, Gap, Zara, Mango and Uniqlo. It has a plant in Nicaragua and is building factories in Indonesia and Vietnam.
"As a company... we see this as a huge opportunity to invest and grow," said Sae-A Trading chairman W.K. Kim.
"We hope that the addition of our exports will double Haiti's current apparel export volume within the next eight years."
The US State Department said in a separate statement the Korean firm would become Haiti's biggest private employer.
"Training 20,000 people will be no small challenge in itself.... This will create additional opportunities for schools and training institutes," said Kim.
The industrial complex will include some 5,000 homes nearby and create 15,000 more jobs on top of Sae-A's employees when the first phase is built. It is scheduled to begin operations in the first quarter of 2012.
The project will also involve building roads and ports nearby.
The State Department said the park when fully developed would support 65,000 permanent jobs. The US government will provide more than $120 million to help develop it, with another $50 million coming from the IADB.
Haiti exported apparel worth $512 million to the United States in 2009, nearly 90 per cent of its total exports and about 10 per cent of its gross domestic product.
Accelerating Haiti's recovery will be the "absolute priority" of UN aid agencies this year, the United Nations said Tuesday -- almost a year after the earthquake on January 12, 2010, that left 225,550 people dead and 2.3 million displaced.
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