By Alexander Marrow MOSCOW (Reuters) -Shares in Russia’s largest children’s toy retailer Detsky Mir slumped on Friday after its shareholders agreed to restructure the business in the form of a spin-off that could pave the way for the company to become private. Detsky Mir, whose free float exceeds 50% and counts a host of Western funds and banks among its shareholders, in November said it was planning a gradual transformation into a private company, citing the need to maintain steady business operations. Elements of the company’s restructuring could serve as a template for other Russian firms w…