Abstract: In a method for distributing securities of portfolio items among a plurality of internal portfolios, each portfolio item has a determined number of securities distributed over each internal portfolio according to a determined consolidation ratio (CRC.sub.i,,j-1) attributed to each internal portfolio. A total value (PV.sub.j-1) of the portfolio items is determined and a transaction assigned to one portfolio item within one internal portfolio is received, having a transaction value (NCA.sub.i). A further consolidation ratio (CRC.sub.i,j) is determined for each internal portfolio based on the consolidation ratio (CRC.sub.i,j-1), total cash assets (PV.sub.j-i), and the transaction value (NCA.sub.i). In a further step, a transfer of a determined number of securities is performed, for each portfolio item, from each internal portfolio to the one internal portfolio to which the transaction is assigned.