The Mott metal-insulator transition in the multi-band Hubbard model in infinite dimensions is studied by using the linearized dynamical mean-field theory. The critical interaction U-c is obtained analytically. For the symmetric case and for orbital degeneracy M we find U-c = (4M + 2)rootL(2) where L-2 is the second moment of the non-interacting density of states. We also derive an analytical expression for the discontinuity of the chemical potential mu(n) at the filling n = M for U > U-c. The findings are in good agreement with numerical results obtained from the exact diagonalization method. (C) 2003 Published by Elsevier Science B.V.