Ferries are seen docked at the Port of Piraeus, southwest of central Athens, on November 12, 2015

Greece's privatisation agency announced Wednesday it had accepted a 368.5 million-euro ($402.4 million) bid for 67 percent of the Port of Piraeus by China's COSCO.

"HRADF's Board of Directors evaluated the improved economic offer, taking into account the two existing valuations for (the Piraeus Port Authority) and decided to declare COSCO (Hong Kong) Group Limited as the preferred investor," the privatisation agency said in a statement.

It called the deal, which also includes 350 million euros of investment into the port plus revenues of 410 million to go to the state, "a very important milestone" in the Greek government's privatisation programme.

The China Ocean Shipping Company was the only bidder for the majority stake in the port, Greece's largest and one of the busiest in Europe.

Denmark's APM and International Container Terminals Services of the Philippines had also expressed interest in Piraeus, but did not submit bids.

COSCO through a subsidiary manages the two main container terminals at the port under a 35-year concession signed in 2008, with the objective of making Piraeus a key port of entry for Asian goods into Europe.

The privatisation of the port has been postponed several times in recent years, with the arrival of the leftist government of Prime Minister Alexis Tsipras putting it on ice last year.

But as part of an 86-billion ($94 billion) bailout last year needed to keep Greece in the eurozone, Tsipras agreed to move forward on the privatisation of a number of companies.

Workers at the port have recently gone on strike and demonstrated against the sale at what they feared would be too cheap a price.

The Greek government plans to keep a stake in the port, which is listed on the Athens stock exchange.