Pressure induced high-spin (HS) to low-spin (LS) transition in MnS2 was speculated by Chattopadhyay and von Schnering more than twenty years ago from their high pressure X-ray diffraction investigation that showed structural phase transition accompanied by a volume collapse at Pc = 130 kbar. We did high-pressure low-temperature investigations on MnTe2 on D20 at ILL and on PEARL at ISIS. In our D20 experiment at ILL the signal to background ratio was very small due to the large background scattering from the pressure cell. The diffraction pattern obtained on PEARL had a smaller background but we could not access low-Q magnetic reflections. Also we could not cool the pressure cell below about 90 K. The new upgrade of the PEARL high pressure diffractometer will enable us to study HS-LS transition in MnS2 and MnTe2. We request 5 days beam time on PEARL for the proposed experiment.