Inertial regimes in a channel flow of suspension of finite-size neutrally buoyant particles are studied for a wide range of Reynolds numbers: 500 ≤ Re ≤ 5000, and particle volume fractions: 0 ≤ Φ ≤ 0.3. The flow is classified in three different regimes according to the phase-averaged stress budget across the channel [2]. The laminar viscous regime at low Re and Φ where the viscous stress is the dominating term in the budget, the turbulent regime at high Re and relatively low Φ where the momentum is mainly transferred by the action of the Reynolds stress and the inertial shear-thickening regime where the particle stress contributes the most to the significant enhancement of the wall shear stress. Particle distribution and dispersion properties provide additional evidence for the existence of the three different regimes.