  We formulate a model of spacetime with inhomogeneous matter distribution in
multiple domains. In the context of the backreaction framework using Buchert's
averaging procedure, we evaluate the effect of backreaction due to the
inhomogeneities on the late time global evolution of the Universe. Examining
the future evolution of this universe, we find that it can transit from the
presently accelerating phase to undergo future deceleration. The future
deceleration is governed by our model parameters. We constrain the model
parameters using observational analysis of the Union 2.1 supernova Ia data
employing the Markov Chain Monte Carlo method.
