** Shares of Australia's Rio Tinto RIO.AX reverse course to fall as much 0.3% to A$172.04
** Stock up as much as 1% to A$174.27 earlier in the session
** The miner says it has relatively limited visibility of how the ongoing conflict will affect supply chains in second half
** Says direct impact from the Middle East conflict on its operations have been limited so far on the supply end, while company's commodity prices have responded favourably
** Company posts a 13% rise in first-quarter Pilbara iron ore production (100% basis)
** Says Pilbara iron ore sales up 2% in the three-month period ended March
** Rio Tinto stock up 17.4%, YTD
(Reporting by Sneha Kumar in Bengaluru)
((Sneha.kumar@thomsonreuters.com;))