  We analyze multi-wavelength data of a M7.9/1N class solar flare which
occurred on 27 April, 2006 from AR NOAA 10875. GOES soft X-ray images provide
the most likely signature of two interacting loops and their reconnection,
which triggers the solar flare. TRACE 195 A images also reveal the loop-loop
interaction and the formation of `X' points with converging motion (~30 km/s)
at the reconnection site in-between this interacting loop system. This provides
the evidence of progressive reconnection and flare maximization at the
interaction site in the active region. The absence of type III radio burst
during this time period indicates no opening of magnetic field lines during the
flare energy release, which implies only the change of field lines
connectivity/orientation during the loop-loop interaction and reconnection
process. The Ondrejov dynamic radio spectrum shows an intense decimetric (DCIM)
radio burst (2.5--4.5 GHz, duration ~3 min) during flare initiation, which
reveals the signature of particle acceleration from the reconnection site
during loop-loop interaction. The double peak structures at 4.9 and 8.8 GHz
provide the most likely confirmatory signature of the loop-loop interaction at
the flare site in the active region. RHESSI hard X-ray images also show the
loop-top and footpoint sources of the corresponding two loop system and their
coalescence during the flare maximum, which act like the current carrying
flux-tubes with resultant opposite magnetic fields and the net force of
attraction. We also suggest that the shear motion/rotation of the footpoint of
the smaller loop, which is anchored in the opposite polarity spot, may be
responsible for the flare energy buildup and then its release due to the
loop-loop interaction.
