Woburn (Mass.) Contributory Retirement System is considering replacing a $4.8 million high-yield mutual fund investment with an active manager, according to a source at plan consultant Wainwright Investment Counsel who asked not to be named. Finalists will likely be named in September. Officials for the $94 million pension fund are considering replacing the mutual fund manager for organizational reasons; further information was not available by press time. According to the Money Market Directory, the fund's fixed-income managers are Babson Capital Management and Wellington Management. Maureen Marcucci, Woburn retirement administrator, referred all questions to Wainwright.