  Propagation of a weak probe pulse through a $\Lambda$ system in a resonant
gain configuration is investigated. We employ the control field intensity that
permits the amplification of probe pulse during propagation, without
instability at two photon resonance. Posterior to amplification, a broadened
probe pulse is obtained, which retains its initial pulse shape and travels at
the speed of light in vacuum, without experiencing any delay, absorption, and
dispersion. The salient feature of this technique lies in the fact that in
addition to preserving the initial pulse shape, it also ensures stable pulse
propagation after amplification. It also works for arbitrary probe pulse
shapes.
