Lepton Flavour Violation and Baryon Number Non - conservation in τ → Λ + h

τ − → Λπ− and τ− → ΛK− as well as the (B−L)-violating modes τ− → Λπ− and τ− → ΛK− using 237 fb of data collected with the BABAR detector at the PEP-II asymmetric-energy ee storage rings. We do not observe any signal and we determine preliminary upper limits on the branching fractions B(τ− → Λπ−) < 5.9 × 10, B(τ− → Λπ−) < 5.8 × 10, B(τ− → ΛK−) < 7.2 × 10, and B(τ− → ΛK−) < 15 × 10 at 90% confidence level.