Member States may provide that , for the calculation of the solvency margin as provided for by this Directive , insurance undertakings subject to supplementary supervision in accordance with Directive 98/78 / EC or to supplementary supervision in accordance with Directive 2002/87 / EC , need not deduct the items referred to in ( a ) and ( b ) of the third subparagraph of this Article which are held in credit institutions , investment firms , financial institutions , insurance or reinsurance undertakings or insurance holding companies which are included in the supplementary supervision .