** London-listed shares of refractory products supplier RHI Magnesita NV RHIM.VI, RHIM.L surge 15.5% to 2,305p
** Top gainer on FTSE Mid 250 index .FTMC, which is up 0.86%
** Company posts 12.7% EBITA margin in July-Oct period vs 8.4% in H1, showing significant operational improvement
** Co says on track to deliver full-year adjusted EBITA of 370mln-390mln euros (about $431mln-$454mln)
** Peel Hunt notes guidance reiteration "encouraging" amid cautious Q3 updates from European steel mills
** YTD, stock down nearly 29%
($1 = 0.8575 euros)
(Reporting by Tuhina in Bengaluru)
((Tuhina@thomsonreuters.com))