In the 1990s, many major employers in the United Kingdom have moved to more open internal job markets (OIJMs). OIJMs give the job of filling internal vacancies to line managers and employees who see the job advertised and apply for it. The development and operation of OIJMs at the following firms were studied: Rolls-Royce; British Gas Trading; Halifax plc (public limited company); and the United Kingdom's Civil Service, Her Majesty's Customs and Excise, and the Department of Trade and Industry. The study revealed that, although they have generally been welcomed by managers and employees, OIJMs have also spawned a number of concerns on the parts of line managers involved in filling vacancies, employees, and human resources (HR) managers. Key issues related to OIJMs that must be addressed include the following: the OIJM process's slowness and labor intensiveness; rules driving out judgment; too many or too few applicants and job moves; fairness and diversity; succession planning and open markets; and the role of HR and quality control. A model for good practice in OIJMs was proposed that emphasizes clear communication and a sense of balance. (Ten figures are included. A checklist for reviewing an OIJM process is appended.) (MN)