  Using the framework of the Heavy Quark Effective Theory we have re-analyzed
the Isgur-Wise function describing semileptonic \Lambda_b to \Lambda_c decays
in the QCD sum rule approach. The slope parameter of the Isgur-Wise function is
found to be \rho^2 = 1.35 \pm 0.12, which is consistent with an experimental
measurement and a lattice calculation. To O(1/m_b,1/m_c) of the heavy quark
expansion the integrated \Lambda_b decay width is used to extract the CKM
matrix element V_{cb} for which we obtain a value of |V_{cb}| = 0.041 \pm 0.004
in excellent agreement with the value of |V_{cb}| determined from semileptonic
B to D^* decays.
