Balloon-borne experiments using omnidirectional scintillation detectors that measured X ray with energies between 30 and 150 keV in the atmosphere were conducted during 1981 from S¿o Jos¿ dos Campos-Brazil (geographic coordinates 23¿12'S, 45¿51'W and L~1.13). The measurements detected an intensification in the X ray flux in association with a strong geomagnetic storm. The enhancement in the flux in this energy range, attributed to electron precipitation, was determined to be ~7¿10-3 photons cm-2 s-1 keV-1 at 5 g cm-2. The results are compared to similar ones obtained in the region of the South Atlantic Magnetic Anomaly and their implications are discussed briefly in the context of local energetic electron precipitation.