The deal was signed in South Korea by executives of SK, its US partner Shaw Group and Egyptian firm Carbon Holdings, the company said in a statement.
The plant capable of producing 1.35 million tonnes of ethylene a year will be built in the Ain Sokhna industrial complex 120 kilometres (72 miles) east of Cairo, it said.
The Korean company said construction would be completed in 2016.
Copyright AFP (Agence France-Presse), 2011