Logo of Gazprom. (data chart) Overseas network, May 12 (Xinhua) according to Bloomberg news, another 10 European natural gas buyers have opened ruble accounts in Gazprom in order to be able to buy natural gas in rubles as required by Russia. So far, the number of European companies opening ruble accounts has doubled from the end of April to 20. The report quoted people familiar with the matter as saying that in addition to 20 European companies opening accounts, 14 companies asked for documen...