** Shares of Mondi MNDI.L down 5.1% at 798.8p
** Stock top percentage loser on FTSE 100 .FTSE, which is down ~0.4%
** British paper and packaging company posts Q1 underlying core profit of 212 mln euros ($247.55 mln) vs 290 mln euros a year ago on a challenging paper-market industry
** Co to raise prices as Middle East conflict leads to higher energy, raw material and logistics costs
** Co to close three converting plants, reducing headcount by 450 over course of year
** YTD, MNDI stock has fallen ~7%, .FTSE up 5.3%
($1 = 0.8564 euros)
(Reporting by Akshaya V in Bengaluru)
((akshayav@thomsonreuters.com))