Casual vacancy of auditor

Dear Friends,

I have a query regarding Auditors resignation and subsequent appointment of auditor. Auditor of a pvt.ltd.co. was appointed for2013-14, but now he wants to resign and dont agree to sign the audit report for 2013-14...can an auditor do this as F.Y.is over...even if he can..what should be the right course of action for both auditor and co. for his resignation and appointment of new auditor and consequential filling to ROC.