The company said it will choose the best suitable shipyards from Hudong Zhonghua Shipbuilding, Jiangnan Shipbuilding, Imabari Shipbuilding, Samsung Heavy Industries and Hyundai Heavy Industries to construct the ships.
Evergreen expects to spend $2.3bn to $2.6bn on the construction of the ships.
The 300,000 extra slots will give Evergreen a fleet of around 1.6m slots. Alphaliner data shows Evergreen currently operates a fleet of 197 ships with a total capacity of 1.28m teu, making it the seventh largest containerline in the world.
It currently has an orderbook of 60 ships with a total capacity of around 454,200 teu.
