S&P also affirmed SLM's BBB-minus rating. While a recent sale of residual interests in the SLM Student Loan Trust securitization 2007-4 is modest, "we believe this represents a shift in the company's strategy related to its Federal Family Education Loan Program (FFELP) portfolio," the rating agency said in a statement. "The negative outlook reflects our belief that SLM could undertake additional similar transactions, which would reduce future cash flows from the company's FFELP portfolio." Copyright Reuters, 2013