Rallye, whose subsidiary Casino also owns top French high-street supermarket brands like Monoprix and Franprix, said late on Thursday that it had sought bankruptcy protection to reorganise its €3 billion-euro debt load. Following trading suspensions the day earlier, Rallye shares lost over half their value on Friday morning, plunging 54 percent on the Paris stock exchange to trade at €3.50 before rebounding slightly. READ ALSO Is the french hypermarché on its last legs But Rallye said on Friday that Casino as well as sports chain Go Sport, which it also owns, "were not concerned" by the proceedings, which involved only the majority shareholder. As a consequence, Casino shares surged by more than 16 percent on the Paris stock exchange to €32.52. But since March, Casino shares are still down more than 30 percent.