Exelon Corporation 's ( EXC ) unit, Commonwealth Edison Company (ComEd), has conducted a bond market transaction, thereby pricing its 4.60% First Mortgage Bonds worth $350 million. The bonds will mature on Aug 15, 2043. The offering will close on Aug 19. Exelon intends to utilize the net proceeds of the issue to repay a part of its outstanding commercial paper obligations and use the remaining for general corporate purposes. It is a normal practice of the companies to issue new bonds having a lower coupon rate for redeeming debts while reducing interest costs and extending repayment tenure. Exelon and its subsidiaries issue bonds and notes from time to time and collect funds to repay its existing debts and for other purposes. Exelon's unit, Baltimore Gas and Electric Company, issued notes in Jun 2013. The company utilized the net proceeds from the issue to repay a part of its existing notes and used the rest for general corporate purposes.