This excerpt taken from the E 20-F filed Jun 21, 2006.
Receivables and financial assets to be held to maturity
Receivables and financial assets that must be held to maturity are stated at cost represented by the fair value of the initial exchanged amount adjusted to take into account direct external costs related to the transaction (e.g. fees of agents or consultants, etc.). The initial carrying value is then corrected to take into account capital repayments, devaluations and amortization of the difference between the reimbursement value and the initial carrying value; amortization is carried out on the basis of the effective internal rate of return represented by the rate that equalizes, at the moment of the initial revaluation, the current value of expected cash flows to the initial carrying value (so-called amortized cost method). The economic effects of the valuation according to the amortized cost method are charged as "Financial income (expense)".