Madison Dearborn Partners said Monday it has agreed to invest in Aderant Holdings. The sellers are Vista Equity Partners and company management, which will retain “significant” ownership positions. Financial terms weren’t announced. MDP is buying about half of Vista Equity’s and Aderant management’s stakes, the statement says. Atlanta-based Aderant provides business management software for law and professional services firms. BofA Merrill Lynch provided financial advice to MDP, while BMO Capital Markets and Marks Baughan advised Aderant and Vista.