An expanding investigation into conflicts of interest in the student-loan industry continued to sweep up more lenders and college financial-aid administrators last week. The nation's largest student-loan provider, Sallie Mae, accepted a $2-million settlement with New York State's attorney general, Andrew M. Cuomo, and three more college officials were put on administrative leave for questionable ties to lenders, while dozens of their colleagues at institutions across the country came under scrutiny for their roles on loan-company advisory boards. U.S. Representative George Miller, chairman of the House education committee and a California Democrat, announced plans to hold a committee hearing on April 25 at which Cuomo will testify about his investigation that certain bank-college relationships may be defrauding students from New York State. That investigation, along with the threat of Congressional action under Democratic control on Capitol Hill, has already prompted several banks that make student loans to reconsider their use of advisory boards, in which directors and other officials from college student-aid offices meet with the banks to discuss ways of working more cooperatively.