  Solvency II Directive 2009/138/EC requires an insurance and reinsurance
undertakings assessment of a Solvency Capital Requirement by means of the
so-called "Standard Formula" or by means of partial or full internal models.
Focusing on the first approach, the bottom-up aggregation formula proposed by
the regulator permits a capital reduction due to diversification effect,
according to the typical subadditivity property of risk measures. However, once
the overall capital has been assessed no specific allocation formula is
provided or required in order to evaluate the contribution of each risk source
on the overall SCR. The aim of this paper is to provide a closed formula for
capital allocation fully coherent with the Solvency II Capital Requirement
assessed by means of Standard Formula. The solution proposed permits a top-down
approach to assess the allocated SCR among the risks considered in the
multilevel aggregation scheme established by Solvency II. Besides, we
demonstrate that the allocation formula here proposed is consistent with the
Euler's allocation principle
