  We present the first evidence for B semileptonic decays into the charmed
baryon Lambda_c+ based on 420 fb-1 of data collected at the Upsilon(4S)
resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are
tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We
measure the relative branching fraction BF(Bbar -> Lambda_c+ X l-
nubar_l)/BF(Bbar -> Lambda_c+/Lambda_c- X) = (3.2 +/- 0.9_stat +/- 0.9_syst)%.
The significance of the signal including the systematic uncertainty is 4.9
standard deviations.
