Study of the decays ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Xi }}^0$${\mathit{K}}^{+}$, ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Sigma }}^{+}$${\mathit{K}}^{+}$${\mathit{K}}^{\mathrm{-}}$, and ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Xi }}^{\mathrm{-}}$${\mathit{K}}^{+}$${\mathrm{\pi }}^{+}$

We report the measurement of new modes of the charmed baryon ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$ using data recorded by the CLEO II detector at the Cornell Electron Storage Ring. We find branching ratios, relative to ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathit{pK}}^{\mathrm{-}}$ ${\mathrm{\pi }}^{+}$, of 0.070±0.011±0.011 for ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Sigma }}^{+}$ ${\mathit{K}}^{+}$ ${\mathit{K}}^{\mathrm{-}}$, 0.069±0.023±0.016 for ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→Σφ, 0.078±0.013±0.013 for ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Xi }}^0$ ${\mathit{K}}^{+}$, and 0.053±0.016±0.010 for ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Xi }}^{\mathrm{*}0}$ ${\mathit{K}}^{+}$. These measurements indicate that W-exchange diagrams contribute to ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$ decay. We have also made a new measurement of the previously found mode ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathrm{\Xi }}^{\mathrm{-}}$ ${\mathit{K}}^{+}$ ${\mathrm{\pi }}^{+}$.