This document concerns the proposal to negotiate amendments to an existing contract for the supply, installation and modification of air-handling systems for the LHC. For the reasons explained in this document, the Finance Committee is invited to approve amendments to the existing contract for the supply, installation and modification of air-handling systems for the LHC with AMEC SPIE (DE) for a total amount not exceeding 2 563 080 euros (3 900 000 Swiss francs), not subject to revision, bringing the total contract amount to a maximum of 10 785 570 euros (16 411 390 Swiss francs), not subject to revision. The rate of exchange used is that stipulated in the initial tender