A Delaware federal judge ruled Tuesday that Navient Corp., one of that nation’s largest servicers of student loans, must face claims that it had pumped up its stock price by hiding serious problems with its loan portfolio and other risks from investors.

The ruling, from U.S. District Judge Maryellen Noreika, trimmed some claims from the securities class action, but also found reason to believe that top executives at the Wilmington-based Sallie Mae spin-off knew the firm was under-reporting the number of delinquent accounts on its books.