April 5 (Reuters) - Rio Tinto Plc RIO.L -
* Australian Commissioner Of Taxation has issued amended income tax assessments to Rio Tinto for calendar years 2010 to 2013
* Amended income tax assessments require co to pay additional tax of A$379 million plus interest of A$68 million, a total of A$447 million
* Amended assessments do not relate to any tax avoidance schemes as confirmed by Australian tax office
* Issue in dispute is pricing of certain transactions between Rio Tinto entities based in Australia and group's commercial centre in Singapore
* Considers that its pricing is in accordance with internationally recognised OECD guidelines and Australian domestic law
* Rio Tinto will challenge amended tax assessments, but will pay 50 percent of total amount to ATO this month
* Seek double taxation relief in accordance with Australia-Singapore double tax treaty.
* Transfer price in dispute is in line with an outcome agreed by ATO for years prior to 2010 Source text for Eikon: ID:nRSE6782Ba Further company coverage: RIO.L