A multiwavelength study of an M-class flare and the origin of an associated eruption from NOAA AR 11045

► Multiwavelength study of an M-class flare and eruption from AR11045 on 7 February 2010. ► The magnetic field changes from dipole to quadrapole regime resulting in eruptions. ► The change in magnetic field is caused due to flux emergence and photospheric flows. ► The reconnection generated detached flux tube may be associated with a halo CME.