Nanosized La0.7Sr0.3MnO3/Pr0.5Sr0.5MnO3 (LSMO1-xPSMOx) ceramic composites are prepared by solid-state co-sintering of ultrafine ferromagnetic LSMO and anti -ferro magnetic PSMO powders. The n-ftrostructural, electro- and magneto-transport properties of the composites are characterized. Both the anti-ferromagnetic/ferromagnetic coupling between PSMO/LSMO phases at low temperature and ferromagnetic ordering of PSMO at high temperature make a contribution to the enhanced low-field magnetoresistance. This effect decays more slowly than that for pure LSMO with increasing temperature up to 250 K. (C) 2002 Elsevier Science B.V. All rights reserved.