• on whose capacities the tenderer relies upon to fulfil the selection criteria as  described under  Section 3.2 ; • whose individual share of the contract, known at the time of submission, is above  20 %.  • any new subcontractor is not in an exclusion situation;  • the tenderer still fulfils the selection criteria and the new subcontractor fulfils the  selection criteria applicable to it individually, if any;  • the terms of the originally submitted tender are not altered substantially, i.e. all the  tasks assigned to the former subcontractor are taken over by another involved  entity, the change does not make the tender non-compliant with the Tender  specifications, and the evaluation of award criteria of the originally submitted tender  is not modified.  2.4.3. Entities on whose capacities the tenderer relies to fulfil the  selection criteria  Any such subcontractor must provide the tenderer with a commitment letter drawn up in  the model attached in  Annex 5.1  and signed by its authorised representative. Changes concerning subcontractors identified in the tender (withdrawal/replacement of a  subcontractor, additional subcontracting) during the procurement procedure (after the  submission deadline and before contract signature) require the prior written approval of  the  Contracting authority  subject to the following verifications:  Subcontracting to subcontractors identified in a tender that was accepted by the  Contracting authority  and resulted in a signed contract, is considered authorised.  In order to fulfil the selection criteria a tenderer may also rely on the capacities of other  entities, regardless of the legal nature of the links it has with them. It must in that case  prove that it will have at its disposal the resources necessary for the performance of the  contract by producing a commitment letter in the model attached in  Annex 5.2,  signed by  the authorised representative of such an entity, and the supporting evidence that those  other entities have the respective resources.  If the contract is awarded to a tenderer intending to rely on another entity to meet the  minimum levels of economic and financial capacity, the  Contracting authority  may require  the entity to sign the contract or, alternatively, to provide a joint and several first-call  financial guarantee for the performance of the contract.  With regard to technical and professional selection criteria, a tenderer may only rely on  the capacities of other entities where the latter will perform the works or services for which  these capacities are required (i.e. the latter will assume the role of subcontractors).    Relying on the capacities of other entities is only necessary when the capacity of the  tenderer is not sufficient to fulfil the required minimum levels of capacity. Abstract  commitments that other entities will put resources at the disposal of the tenderer will be  disregarded.  13