The Supreme Court on Sunday fixed July 31 for hearing a leave-to-appeal petition filed by BNP Chairperson Khaleda Zia seeking a stay on the trial in the Niko corruption case against her.Chamber Judge of the Appellate Division Justice Hasan Foez Siddique fixed the date.Khaleda Zia filed the petition in 2015 challenging a High Court verdict that had cleared the way for running the trial proceedings of Niko graft case.The HC on June 18, 2015 rejected a petition filed by Khaleda challenging the legality of the trial proceedings of the case filed by the ACC.