The theory of micelle formation in a dilute solution mixture of polyelectrolyte/neutral diblock copolymers and oppositely charged linear chains has been developed. The core of the micelles is formed by the hydrophobic monomer units of polyelectrolyte complexes between the oppositely charged polyions while the hydrophilic uncharged blocks of the block copolymers comprise the micellar corona. The process of the formation of polyelectrolyte complexes and micelles in the solution has been described as sets of association-dissociation reactions with certain chemical constants and the concentration distribution of micellar aggregates of a given composition has been calculated for various concentrations of linear chains and block copolymer macromolecules in the solution. It was shown that the micelles are formed by nearly fully neutralized block copolymers, so that the micellar charge is close to zero. The aggregation number of the micelles and their charge slightly depend on the concentration of the block copolymers as well as the linear chains in the solution. Micelles in the solution coexist with single block copolymer chain/linear polymer complexes of different composition. (C) 2003 American Institute of Physics.