MOSCOW, Dec 10 (Reuters) - Liquefied natural gas (LNG) export volumes from Russia declined by 70% in October from September to 2 million cubic metres, according to customs data published on Thursday. They was also sharply down from 9.4 million cubic metres in October 2019. There are two major LNG producing plants in Russia: Yamal LNG, led by Novatek, and Sakhalin 2, led by Gazprom . There was no explanation for the exports decline and no breakdown of the data. The customs data also showed that sales of LNG fell by 85% in October from September to $67.2 million. According to the statistics, volumes of Russian LNG exports rose in January-October by 1.8% year-on-year to 57.1 million cubic metres. They generated sales of almost $6 billion for the period, down 15%, amid weaker prices. (Reporting by Oksana Kobzeva; writing by Vladimir Soldatkin; editing by Mark Potter)