We present electron spin resonance (ESR) data at 9.4 GHz in the phase separated Pr0.65Ca0.25Sr0.10MnO3 manganite. The coexistence of two resonance lines are observed below the short-range magnetic-order temperature (Ts≈255K). One of the ESR line is a paramagnetic contribution retained from the high-temperature phase. The second contribution appears at Ts, which is associated with the presence of ferromagnetic regions. The two contributions can be seen near the charge-order transition, 7co≈210K. We study the temperature evolution of the resonance field and the linewidth of the ESR lines.