A Multimonopole Solution in String Theory
  A multimonopole solution in Yang-Mills field theory is obtained by a modification of the 't Hooft ansatz for a four-dimensional instanton. Although this solution has divergent action near each source, it can be used to construct an exact finite action multimonopole solution of heterotic string theory, in which the divergences from the Yang-Mills sector are precisely cancelled by those from the gravity sector. 
Ramzi R. Khuri