* China's COSCO eyes Greek rail network - sources
* Already sole bidder for Greece's Piraeus Port
* Buying both would give COSCO a European transhipment hub
By Angeliki Koutantou and Brenda Goh
ATHENS/SHANGHAI, Feb 5 (Reuters) - China's COSCO is expected to make an offer for Greece's rail network after becoming the sole bidder for the country's largest port, two people familiar with the matter said, as the state owned shipping giant forges ahead with a plan to build a European transhipment hub.
Buying TRAINOSE and Piraeus Port would give COSCO maritime connections to the Suez Canal and rail links to the Balkans and central and Eastern Europe.
Bolstered by December's merger with China Shipping Group , COSCO's focus on Greece is about building market share at a time of anguish in a bruised and oversupplied shipping sector, industry sources said.
It also fits with China's "One Belt, One Road" policy of building a modern Silk Road to boost trade and create an outlet for Chinese industrial powerhouses caught up in the global downturn and slower growth at home.
COSCO was unchallenged in its $400 million offer for a 67 percent stake in Piraeus Port last month and is set to be named the preferred investor.
But it could face competition for the rail network, including from U.S. railroad holding company Watco, one of the individuals said, after Greece relaunched the tender in an effort to drum up more interest. TRAINOSE has an estimated value of dozens of millions of euros.
"COSCO and Watco are interested in TRAINOSE," said the source, who declined to be identified. "There is also a Greek group which is interested and is looking for a partner."
A COSCO spokeswoman declined to comment on prospective bids for other Greek assets. She said the firm believed buying Piraeus would improve the port's competitiveness and efficiency, but declined to elaborate on detailed plans.
Watco could not be reached for comment and the source did not identify the Greek group.
Privatisation agency HRADF had invited suitors for TRAINOSE, the sole provider of rail services in Greece, to express interest from Feb. 1.
Officials in Greece have said it is too early to comment on specifics, but a sale is almost inevitable: a separate source close to the matter said that without a sale TRAINOSE could be forced to return millions of euros in state subsidies to the European Union.
The leftist government of Prime Minister Alexis Tsipras opposes privatisations and halted the sale of the port and other state assets after winning elections in January last year. The process resumed under a third international bailout of up to 86 billion euros ($94 billion) that was agreed in August.
Piraeus Port, near Athens, has flourished under the management of Cosco Pacific, a listed COSCO unit that took over under a 30-year concession in 2009.
It has been credited with growing container throughput from 166,000 twenty foot equivalent units (TEU) in 2009 to almost 3 million TEU in 2014.
"Piraeus is already a success. To develop it further, one condition is that the infrastructure connections with other parts of Europe must be developed," said Frans-Paul van der Putten, senior research fellow at Dutch think-tank Clingendael.
COSCO is also among the investors expected to bid for the development and operation of a 250 million euro Greek freight centre with access to the national railway network and Piraeus Port, a Greek government official said on Wednesday. Binding bids are expected to be submitted by May 31.
Piraeus, a gateway for COSCO and other Asian groups, is a faster route from Asia than northern European alternatives, and COSCO already attracts multinationals like Huawei and Samsung Electronics distributing into Europe and beyond.
It has a 2013 deal with TRAINOSE and U.S. electronics maker Hewlett-Packard , which uses Piraeus as the main distribution centre for its products in Europe.
"I think any port or related investments around the Mediterranean - not just in Greece but also in Turkey, North Africa and the Black Sea - will be of interest," said Jonathan Beard, vice president at transport consultancy ICF International in Hong Kong.
Cosco Pacific owns stakes in terminals at the Suez Canal and Antwerp in Belgium, while rival Merchants Holdings has interests in terminals in Malta, Morocco and France. (Reporting by Angeliki Koutantou and Brenda Goh, with additional reporting by Jonathan Saul in LONDON, Renee Maltezou in ATHENS and Keith Wallis in SINGAPORE; Editing by Dean Yates and Clara Ferreira Marques)