Sallie Mae, the student-loan giant, gave Delaware a shot in the arm last month when it settled on suburban Wilmington for the location of its new operations center and 1,100 jobs.
 To house those workers, CB Richard Ellis Inc. said today that Sallie Mae has agreed to pay $20.75 million to Nationwide Financial for its building at 300 Continental Drive, near Newark, Del. The property includes 160,000 square feet of offices, on 22 acres off I-95 between Wilmington and Newark.
  Nationwide bought the building when it took over the former Provident Mutual Life Insurance Co. of Berwyn in 2003, but doesn't need all the space. It will lease back almost half the total -- 72,000 square feet -- next year. Nationwide was represented by evp Daniel Reeder and svp John Kaczowka, and CBRE Columbus svp Terry Matthews.