Finance Ministry has proposed a new formula for interest rate calculation in bonds issues under the restructuring scheme for state electric boards (SEBs), sources told NDTV. However, SA Panse, CMD of Allahabad Bank, says that banks will have to take a substantial hit to their net present values (NPVs) if they are given a coupon rate of 10.5-11 per cent on loans converted into bonds. Allahabad Bank, she pointed out, has lent to discoms at an average rate of 12-13 per cent.