Power Grid Corporation (PGC) is planning to raise Rs 1,500 crore through long-term bonds keeping an option to retain over-subscription of the issue, according to market sources. The bond issue will have a stripped tenure with payments ranging from the end of fourth year till the fifteenth year, a bond arranger said, adding the company is seeking an upper cap on the coupon rate at 8.60%. The state-owned company had raised Rs 2,928 crore in late May through bonds at a coupon rate of 8.40%. In early June, the company's subsidiary Vizag Transmission had raised Rs 290 crore at a coupon rate of 8.90% through five-year bonds. Yields had risen in June after RBI said it front-loaded the rate cut which indicated a long pause before another reduction in rates. The Greek crisis had also prevented the yields from coming down. However, the bond market saw an increased volatility over the last two days.