* Tsipras is first serving Greek PM to visit Halki
* Says hopes seminariy, closed in 1971, will one day re-open
* Turkish-Greek ties strained over Cyprus and gas exploration (Recasts with Tsipras visit to seminary)
By Murad Sezer
HEYBELIADA, Turkey, Feb 6 (Reuters) - Greek Prime Minister Alexis Tsipras voiced hope that a closed Orthodox Christian seminary he was visiting in Turkey on Wednesday would be reopened as part of efforts to boost ties long strained by disputes over territory, energy and Cyprus.
Crowds welcomed Tsipras as he arrived on Heybeliada, an island south of Istanbul, to visit the Halki theological school which was closed by the Turkish state in 1971 and has remained a source of contention between the long-time rivals.
“I want to believe that the day is approaching when these rooms will be filled again with the laughter of happy students,” he said in a speech, saying the seminary’s reopening would send a “message of friendship, understanding and brotherhood”.
“There are issues between our governments and our countries which only dialogue can resolve,” he said, flanked by Ecumenical Patriarch Bartholomew, the spiritual head of Orthodox Christians worldwide and who is based in Istanbul.
Tsipras is the first serving Greek prime minister to visit the Halki seminary.
Turkey, which is overwhelmingly Muslim, has given no public indication that it is planning to reopen the Christian seminary and has resisted years of pressure from the European Union, which it aspires to join, to do so.
On Tuesday, Tsipras met Tayyip Erdogan in Ankara, where the Turkish president said he expected more cooperation from Athens in the repatriation of eight soldiers who fled to Greece following an attempted coup in 2016.
Tsipras told their joint news conference that Greece does not welcome putschists, but that the case of the eight soldiers was a matter for the judiciary.
He said both countries had agreed to de-escalate tensions in the Aegean Sea and proceed with confidence-building measures.
Erdogan spokesman Ibrahim Kalin joined Tsipras on Wednesday in Istanbul on a tour of Hagia Sophia, which was the foremost cathedral in Christendom for 900 years and then - after the city fell to the Ottoman Turks in 1453 - one of Islam’s greatest mosques for another 500 years. It has been a museum since 1935.
In late 2017, Erdogan made the first visit to Greece by a Turkish president in 65 years, but the trip was marred by verbal sparring over various historical grievances.
Erdogan complained about discrimination against Muslims in northern Greece, while Turkey’s military presence in ethnically split Cyprus and diverging interpretations of an international treaty defining their borders also fueled tensions.
Cyprus has been divided since a Turkish invasion in 1974 triggered by a brief Greek-inspired coup. U.N.-led peace talks between the Greek and Turkish sides collapsed in 2017.
NATO members Greece and Turkey were nearly drawn into a military clash in 1996 over an uninhabited Aegean islet.
On Tuesday, Turkey updated a list of former military officers wanted for their alleged role in the 2016 putsch to include the eight officers granted asylum in Greece, and offered a bounty of 4 million Turkish lira ($770,000) for each of them. (Additional reporting by Renee Maltezou in Athens; Writing by Daren Butler; Editing by Gareth Jones)