Openwave Systems Inc. said Monday it has signed a deal to sell its mediation and messaging product businesses to Marlin Equity Partners. The deal is expected to close in the month of April. Financial details were not disclosed. Redwood City-based Openwave (NASDAQ:OPWV) is a software innovator and says it invented the mobile Internet. Los Angeles-based Marlin Equity Partners is a private equity firm with more than $1 billion under management. Marlin plans to rename the acquired businesses Openwave...