Pitsiorlas says things are different now. For the first time, the Syriza government has signed up to a privatization program. There is "central support" from the government to proceed, he says.

With a market value of 363 million euros, Piraeus Port earned more from its concession fee from Cosco than its own freight business, according to last year's figures, raking in 36 million euros compared with 23 million euros in revenue from the Pier I operation it runs itself.

A stake in the port operator would also give Cosco exposure to some of the Greek company's profits from its lucrative passenger and car ferry business to the Greek islands. Piraeus is the biggest passenger port in Europe, with some 17 million Greeks and visitors on foot and by car passing through the harbor to the Greek islands.

From his office in Piraeus, with a view of one of the gantry cranes, Vamvakidis is unruffled by the delays and drama. "We're Cosconians," he says, playing on the name of his parent company. "Investments abroad by a country such as China reflect not only the financial aspect. The Chinese are a patient people."