The Oruc Reis research vessel had been scheduled to end its work Thursday, but will now remain at sea until October 27.
Turkey said it will extend a gas exploration mission in the eastern Mediterranean that has raised hackles in neighbouring Greece.
The Oruc Reis research vessel had been scheduled to end its work Thursday, but will now remain at sea until October 27, the Turkish Navy said in a NAVTEX maritime announcement on Wednesday.
Oruc Reis has become the symbol of Ankara's natural gas exploration in the eastern Mediterranean, where discoveries of significant reserves in recent years has triggered a rush for the so-called "blue gold."
Prospective fortunes to be made have reignited long-smouldering rows over maritime borders between Turkey and Greece.
Athens says Ankara is breaking international law by prospecting in Greek waters, including near the island of Meis also known as Kastellorizo.
Ankara says Oruc Reis’ seismic survey activities are carried out within the Turkish continental shelf, and the tiny island of Meis shouldn’t count for imposing Greek sovereignty in the waters.
Oruc Reis' initial deployment in August sparked a weeks-long diplomatic crisis until the ship returned to port last month.
But last week it was sent out again, extinguishing hopes the tensions could be eased.
Greek Prime Minister Kyriakos Mitsotakis on Wednesday has asked the EU to look into suspending its customs union with Turkey.
Tensions in the Eastern Mediterranean
In August, Turkey resumed energy exploration in the Eastern Mediterranean after Greece and Egypt signed a controversial maritime delimitation deal, spurning Turkey's goodwill gesture in halting its search.
Declaring the Greek-Egyptian deal "null and void," Turkey authorised the Oruc Reis to continue activities in an area within Turkey's continental shelf.
Amid tensions over the Mediterranean territory and energy exploration, Turkey has repeatedly stressed its willingness to start negotiations without preconditions, in contrast to Greece's refusal in recent weeks to enter dialogue through both NATO or the EU.
Ankara has consistently opposed Greece's efforts to declare an exclusive economic zone based on small islands near Turkish shores, violating the interests of Turkey, the country with the longest coastline in the Mediterranean.
The country has also said energy resources near the island of Cyprus must be shared fairly between the Turkish Republic of Northern Cyprus and the Greek Cypriot administration.