Negotiate, arrange, concert are comparable when they mean to bring about or accomplish by mutual agreement especially after discussion or parley.
Negotiate and arrange both imply prior exchange of views and wishes and, sometimes, settlement by bargaining or compromise.
Negotiate, however, is somewhat more formal and is especially appropriate when the dealings are carried on by diplomatic, business, or legal agencies, while arrange (see also ORDER ) may retain some notion of its basic idea of putting in order and is especially applicable to dealings tending to the establishment or restoration of order or to those carried on by private persons or their representatives.
Concert implies a planning together and especially a settling upon a joint course of action through conference and negotiation.