Greece has said it plans to sell off stakes in its major ports to strategic investors as to bolster port investment, develop container business and make Greece a regional shipping hub.
Employees at state-controlled Piraeus (OLP) and Thessaloniki ports plan to continue with more strikes in coming weeks, their unions said.
Cargo ships will dock at the ports but will not be allowed to load or unload. The backlog of containers may lead to disruptions in distribution.
"Cargo ships will have to find alternative ports to dock, probably other Mediterranean ports. Merchants will not receive goods on time and these delays will certainly affect the market," said George Nouhoutidis, head of Piraeus port employees union.
Piraeus and Thessaloniki port have a current market value of 769.50 million euros and 370.94 million euros respectively.