This work presents an enhanced model for the reactor-regenerator system of a UOP fluid catalytic cracking (FCC) unit with a high-efficiency regenerator. The model is derived from fundamental principles; relative to earlier versions, a different cracking deactivation model is considered, and the freeboard region in the regenerator vessel is also explicitly addressed. The resulting model is fitted to industrial data, using new correlations to estimate the cracking kinetic constants and other important parameters in the FCC heat balance. In the development of these correlations, only routinely available data and operating variables were considered. As demonstrated, parameter estimation allows a good agreement between the simulated results and the available industrial data. The procedure followed can, therefore; be used to adapt this model to different units of the same class. A comparison of the main features of the steady-state and the dynamic behavior of the validated model with previous results is also considered in this paper.