J.C. Penney Co. may need to pay more than the 135 cents on the dollar it offered yesterday to tender bonds that can restrict the retailer's debt load, according to Gimme Credit LLC.

J.C. Penney's 7.125 percent securities due November 2023 climbed to 144.75 cents on the dollar at 4:23 p.m. in New York to yield 2.3 percent, an increase of 10 cents yesterday and 32.5 cents Monday, according to Trace, the bond-price reporting system of the Financial Industry Regulatory Authority. The company offered to buy back the notes for 130 cents on the dollar and pay an additional 5 cents on the dollar if bondholders consent to amending the indenture, according to a statement today.

"It's likely there will be at least one more round of 'sweetening' the tender offer, considering how important this tender is to the company's financing plans," Carol Levenson, director of research at Chicago-based Gimme Credit, wrote in an e-mail. "On the other hand, given the increase in the price already (probably the most any corporate bond has ever increased in two days barring some kind of 'positive event risk' like an acquisition by a better credit), you probably don't want to be too greedy."