The electrical conductivity, Hall effect and Seebeck coefficient have been measured for single crystals of alloys of HgTe with In₂Te₃ from zero to 37·5% molecular In₂Te₃. Preliminary measurements have been made also in the range 37·5-50%. Electron mobilities near 10 000 cm² V^-1 sec^-1 at 300°K are observed in the 0-37·5% range. The effective mass m_e in this range does not vary much with composition, and is near 0·04 m₀ at 300°K when the electron density is about 3 × 10¹⁷ cm^-3 at that temperature. m_e rises with temperature and with carrier density in the alloys.