The Collaborative International Dictionary of English v.0.48:

neocolonialism \neocolonialism\ n.
   Control by a powerful country of its former colonies (or
   other less developed countries) by economic pressures. In
   contrast to colonialism, in which one country controls
   another territory by military force.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

neocolonialism
    n 1: control by a powerful country of its former colonies (or
         other less developed countries) by economic pressures