The present invention relates to novel crystalline polymorphic and amorphous forms of the compound methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxy-acrylate (azoxystrobin). Infrared Raman spectra, X-ray powder diffraction pattern and differential scanning calorimetry thermogram of two polymorphs “A” and “B” are provided. Further, the present invention also provides methods for preparing the novel polymorphic forms “A” and “B”, as well as processes for producing mixtures of the polymorphs, and a process for preparing amorphous azoxystrobin. Yet further, the present invention provides anti-fungal compositions comprising the novel crystalline polymorphs “A” and “B” or amorphous azoxystrobin, which are useful for controlling and combating fungi grown on agricultural and horticultural crops and up-land, and methods of using the same as pesticidal agents for combating fungi on agricultural and horticultural crops.