GTT's three shareholders-- GDF Suez, the world's biggest utility by market value, French oil company Total and U.S. private equity fund Hellman & Friedman-are planning to sell their stakes, the sources said.
"If any Chinese rival shipbuilder takes over GTT, somehow it will negatively impact (Korean shipbuilders) in the LNG ship market," one source said.
GTT core technology to build LNG (Liquefied Natural Gas) membrane containment systems, used in LNG carriers.
Hyundai and Daewoo declined to comment.
Total wants to sell its 30 percent stake in GTT because it needs to secure funds by selling non-core business in the midst of European debt crisis, another source added.