A suezmax tanker controlled by Piraeus-based NGM Energy was damaged in a collision off the Chinese port of Qingdao on Tuesday.
The Shandong Maritime Safety Administration said the 150,000-dwt A Symphony (built 2001) spilled part of its cargo of oil and had been ordered to anchor some distance from the port.
A 10 nautical mile (18.5 km) exclusion zone has been established around the tanker.
