In this paper, an integral-type sliding mode controller is designed for continuous-time Markovian jump systems based on a singular system approach. The system's dynamical equations include an unknown function denoting the nonlinear uncertainty. The regularity, non-impulsiveness and stochastic stability of the resulting Markovian jump singular system are guaranteed by a new sufficient conditions in terms of strict linear matrix inequalities (LMIs). As a result, stochastic admissibility for sliding mode dynamics is assured. Then, a sliding mode control law is designed such that the closed-loop system's trajectories converge to predefined sliding surfaces in a finite time and remain there for all subsequent times. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.