Greece' Cosco formally sign port of Piraeus privatization

Greek dockworkers fight with Greek riot police officers, during a demonstration in central Athens, Friday, April 8, 2016. The workers were protesting against the deal between Greece and China's shipping giant COSCO for the Athens port of Piraeus, which was signed on Friday. (AP Photo/Lefteris Pitarakis) (The Associated Press)

People wait at a bus stop for the traffic to resume as Greek riot police officers, stand guard following a demonstration by dockworkers in central Athens, Friday, April 8, 2016. The workers were protesting against the deal between Greece and China's shipping giant COSCO for the Athens port of Piraeus, which was signed on Friday. (AP Photo/Lefteris Pitarakis) (The Associated Press)

Greece has formally signed an agreement to sell a 67 percent stake in operating Greece's biggest port to China's Cosco group, a significant step in the debt-crippled country's ambitious privatization drive.

Cosco's 368.5 million-euro ($420 million) offer was approved in January, in a process initially opposed by Greece's left-wing government.

Cosco, owned by the Chinese government, was the sole bidder for the stake in Piraeus Port Authority, a listed company which has a concession to operate the port until 2052.

Greece will retain a 7 percent stake and private investors will hold the remainder.

The deal still needs to be approved by Greece's competition commission and Parliament.

Piraeus is the main gateway to the Greek islands and in 2014 handled 16.8 million passengers.