China's COSCO Shipping, owner of the world's fourth largest container fleet, took a 51 percent stake in Greece's largest port on Wednesday.
The sale of Piraeus Port had been suspended by the leftist-led government when it won elections in January 2015 but talks resumed after Greece agreed an 86 billion euro bailout deal with its euro zone partners.
COSCO agreed to buy 51 percent of Piraeus Port (OLP) in April for 280.5 million euros ($312.51 million) under a deal signed with the HRADF, Greece's privatization agency.
COSCO bought 51 percent of Piraeus Port (OLP) for 280.5 million euros ($312.51 million), acquiring a block of 12.75 million shares in OLP.
COSCO Shipping executive Wan Min rang the opening bell at the Athens bourse at a ceremony to mark the agreement.
Privatization has been a priority of Greece's bailouts since 2010, but political foot-dragging and a highly unionized public sector workforce have slowed progress.
Shares in Piraeus Port, which has a current market value of 350 million euros, were down 0.4 percent to 13.90 euros as of 1016 GMT lagging a Athens share index up 0.46 percent.
COSCO is expected to increase its stake in Piraeus Port to 67 percent over the next five years, HRADF said.
"Should Cosco fulfil certain conditions set out in the agreement, including the successful completion of the mandatory investments up to 300 million euros, it will pay HRADF an additional 88 million euros and increase its stake by 16 percent to 67 percent," it said.
Greece's parliament ratified the sale in June, overcoming some last-minute snags which triggered complaints from the local COSCO representative.
Last month COSCO said it would invest up to 500 million euros in Piraeus Port to upgrade cruise and shipping container facilities.
Operator of one of Piraeus's container terminals since 2009, COSCO has boosted the port's competitiveness.
The port's container throughput stood at 3.36 million 20-foot equivalent units (TEUs) last year, up from 880,000 TEUs in 2010.