Athens - Thousands of containers remained stranded on cargo ships at Greece's largest port of Piraeus on Friday as workers extended by 48 hours a series of strikes in opposition to the takeover of the docks by Chinas COSCO Pacific.

The current strike, which began Monday, has prevented more than 4,000 containers from being unloaded from cargo ships docked at the port.

Trade unions fear businesses could experience shortages during the busy Christmas season if the strike continues, saying they expected more than 60,000 containers to arrive at Piraeus port by mid- December.

Unions are threatening further action unless the contract is annulled.

The deal between the Greek government and the Chinese port operating company was expected to go into effect on October 1, but a strike by dock workers, who said they feared COSCO would cut jobs, delayed the company from taking over until the start of November.

A three-week strike in October cost Greece an estimated 3 million euros (4.4 million dollars) a day, caused hundreds of containers to pile up, and left hospitals dangerously undersupplied as ships carrying basic medical supplies remained stranded at various ports around the Mediterranean.

Workers suspended their strike on October 17 after days of negotiations with the newly elected Socialist government, which said it would renegotiate the deal. Left unconvinced that the government was seeking their best interests, union leaders announced a new strike earlier this week.

The protesters are insisting that the government's contract with the Chinese protect their job security and not curb lucrative overtime hours.

Greece and China signed the 4.3-million-euro (6.3-million-dollar) agreement for the new management of the port at the beginning of the year. The deal is for COSCO to run and upgrade the two piers for up to 35 years.

Piraeus is one of the most important ports in the eastern Mediterranean region. The Chinese company, the worlds seventh largest port operator, plans to make Piraeus the hub of its Chinese exports operation for southeast Europe.

With 2.9 billion euros in trade per year, China is Greece's seventh largest trading partner. (dpa)