** Dutch fertilizer maker OCI OCI.AS jumps about 12%, on track for best day since Dec 2025
** Dutch Enterprise Chamber temporarily blocked OCI's merger with Orascom ORAS.CA, names two independent directors to oversee deal
** Court cited grounds to suspect controlling shareholder Nassef Sawiris's influence, potential harm to minority shareholders
** Dissenting shareholders said deal undervalued OCI
** "This is a major win for the Dutch investor association VEB and other minority shareholders," analysts at ING say in a note
** ING says proposed merger exchange ratio implied about 3 euros/share for OCI versus 4.8 euros/share undisturbed trading, while its last calculated NAV was 6 euros/share
(Reporting by Hugo Lhomedet)
((hugo.lhomedet@thomsonreuters.com))