Online-learning company Edmentum Inc. has closed on $25 million in financing, a deal that allows the company to extend the maturity of its debt, according to a company announcement. New Mountain Finance Corp., a New York-based investment firm, and Santa Monica, Calif.-based Tennenbaum Capital Partners, provided the financing. Both companies were already investors in Bloomington-based Edmentum. Control Data launched Edmentum — then known as Plato Learning — more than 50 years ago.