MOSCOW, Sept 6 (Reuters) - The Fortuna pipelaying vessel on Monday welded the final pipe of the Nord Stream 2 natural gas pipeline's two lines and will lower it to the seabed, the Nord Stream 2 operating company said.

The company aims to start operating the undersea pipeline, which will pump Russian gas to Germany, by the end of the year, it said. (Reporting by Vladimir Soldatkin; Writing by Tom Balmforth; Editing by Edmund Blair)