  We study multipartite entanglement in non-equilibrium quantum phase
transition (NEQPT) attainable in a coherently driven atomic ensemble undergoing
collective decay. The NEQPT arises in the steady state of the system as the
drive field strength is varied in comparison with the decay parameter. A close
connection is observed between the critical behavior and the multi-partite
entanglement in the system determined via the von Neumann entropy. The
derivative of the von Neumann entropy shows Lambda-type behavior typical of the
second order phase transitions. We further show that the calculated bi- and
tri- partite entropies satisfy the Lieb inequality.
