By Yadarisa Shabong and Zandi Shabalala LONDON (Reuters) -Russian hydropower group EN+ is reviewing options for aluminium giant Rusal, in which it is majority shareholder, including turning its international business into a separate entity. Western governments are tightening sanctions on Moscow for its invasion of Ukraine, triggering a disposal of Russian assets and investments worth tens of billions of dollars. EN+ said on Monday that its strategic review of Rusal, in which it owns nearly 57%, was at a preliminary stage and any moves would be subject to “further consideration” as well as talk…