The effect of starting SiC powder (beta -SiC or alpha -SiC), with simultaneous additions of Al2O3 and Y2O3, on the microstructural evolution of liquid-phase-sintered (LIPS) SiC has been studied, When using alpha -SiC starting powder, the:resulting microstructures contain hexagonal platelike alpha -SiC grains with an average aspect ratio of 1.4, This anisotropic coarsening is consistent with interface energy anisotropy in alpha -SiC. When using beta -SiC starting powder, the beta --> alpha phase transformation induces additional anisotropy in the coarsening of platelike SC grains. A strong correlation between the extent of beta --> alpha phase transformation, as determined using quantitative XRD analysis, and the average grain aspect ratio is observed, with the maximum average aspect ratio reaching 3.8. Based on these observations and additional SEM and TEM characterizations of the microstructures, a model for the growth of these high-aspect-ratio SiC grains is proposed.