NEW YORK (AP) ¿ Standard & Poor's Ratings Services raised its corporate credit rating for Hanger Orthopedic Group Inc. Friday, citing earnings growth at the company and a reduction in debt leverage. S&P raised the corporate credit rating to 'B+' From 'B,' both of which are highly speculative. The outlook remains stable, S&P said. Hanger operates rehabilitation centers for people with braces or prosthetics. Shares of Bethesda, Md.-based Hanger jumped 38 cents, or 2.7 percent, to close at $14.50. The stock has traded between $11.10 and $21 over the last 52 weeks. "The stable outlook reflects our expectation that operations will continue to generate upper single digit growth and that the financial risk profile will remain aggressive," S&P said, in a statement.