Roll over of non-convertible portion of partly convertible debt instruments permitted with holder approval, disclosures and credit rating. Regulation 64 permits roll over of the non-convertible portion of partly convertible debt instruments issued by a listed issuer above the specified threshold, subject to Companies Act compliance and conditions: at least 75% holders' approval by postal ballot, circulation of an auditors' certificate on cash flow and liquidity with the resolution notice, issuer undertaking to redeem for dissenting holders, and a credit rating from a registered agency obtained within one month prior to redemption and communicated to holders; creation of fresh security or trust deed is not mandatory if existing documents provide for continuance, with the debenture trustee deciding necessity.