Russian President Vladimir Putin has signed a decree to set up a new operating company for the Sakhalin 2 oil and liquefied natural gas project, Russian media reported, casting the investments of two Japanese firms into doubt. The two major Japanese trading houses Mitsui & Co. and Mitsubishi Corp. could be forced to withdraw from the project in the Russian Far East, as foreign investors must apply within a month to retain their existing shares in the new entity, according to the decree. The decree signed Thursday comes after British oil giant Shell PLC, which has an approximately 27.5 percent …