Merchants on Rakuten Inc.'s online shopping mall have requested that the Japan Fair Trade Commission investigate the e-commerce giant's planned "free shipping" policy, according to sources familiar with the move.Some online stores allege that Rakuten abuses its dominant position to force them to shoulder shipping costs in violation of the antimonopoly law, the sources said Saturday.If the commission orders the operator to revise the policy, it could affect competition with rivals such as Amazon Japan G.K., which ships products at low cost through its own distribution network.The commission …READ FULL ARTICLE