Kobe Steel Ltd.'s bond risk jumped to its highest level in more than three years last quarter as Japan's fourth-largest steelmaker faces increased competition at home and the rising yen erodes profitability overseas.

The cost to insure the firm's debt climbed 115 basis points to 305 in the three months to June 30, according to CMA prices.

That's the highest level since the first quarter of 2009 and more than double the credit-default swaps of South Korea's Posco, which rose 7.7 in the period, the data show. Contracts for the world leader, Europe-based, ArcelorMittal, gained 73 basis points.