2i RETE GAS S.p.A. (incorporated in the Republic of Italy as a joint stock company) €3,500,000,000 Euro Medium Term Note Programme Under this €3,500,000,000 Euro Medium Term Note Programme (the “Programme”), 2i Rete Gas S.p.A. (the “Issuer” or “2iRG”) may from time to time issue notes (the “Notes”) denominated in any currency agreed between the Issuer and the relevant Dealer (as defined below). The maximum aggregate nominal amount of all Notes from time to time outstanding under the Programme will not exceed €3,500,000,000 (or its equivalent in other currencies calculated as described in the Dealer Agreement described herein), subject to increase as described herein. The Notes may be issued on a continuing basis to one or more of the Dealers specified under “Overview of the Programme” and any additional Dealer appointed under the Programme from time to time by the Issuer (each a “Dealer” and together the “Dealers”), which appointment may be for a specific issue or on an ongoing basis. References in this Base Prospectus to the “relevant Dealer” shall, in the case of an issue of Notes being (or intended to be) subscribed by more than one Dealer, be to all Dealers agreeing to subscribe such Notes. An investment in Notes issued under the Programme involves certain risks. For a discussion of these risks see “Risk Factors”. This Base Prospectus has been approved by the Central Bank of Ireland (the “Central Bank”) as competent authority under Directive 2003/71/EC, as amended (including by Directive 2010/73/EU) (the “Prospectus Directive”). The Central Bank only approves this Base Prospectus as meeting the requirements imposed under Irish and EU law pursuant to the Prospectus Directive. Such approval relates only to Notes which are to be admitted to trading on the regulated market of The Irish Stock Exchange plc trading as Euronext Dublin (“Euronext Dublin”) or other regulated markets for the purposes of Directive 2014/65/EU, as amended (“MiFID II”) and/or which are to be offered to the public in any Member State of the European Economic Area. Application has also been made to Euronext Dublin for Notes issued under the Programme to be admitted to trading on Euronext Dublin’s regulated market and to be listed on the Official List of Euronext Dublin. References in this Base Prospectus to Notes being “listed” (and all related references) shall mean that such Notes have been admitted to trading on Euronext Dublin’s regulated market (i.e. Main Securities Market) and have been admitted to the Official List of Euronext Dublin. Euronext Dublin’s regulated market is a regulated market for the purposes of MiFID II. The requirement to publish a prospectus under the Prospectus Directive only applies to Notes which are to be admitted to trading on a regulated market in the European Economic Area and/or offered to the public in the European Economic Area other than in circumstances where an exemption is available under Article 3.2 of the Prospectus Directive (as implemented in the relevant Member State(s)). Notice of the aggregate nominal amount of Notes, interest (if any) payable in respect of Notes, the issue price of Notes and certain other information which is applicable to each Tranche (as defined under “Terms and Conditions of the Notes”) of Notes will be set out in a final terms document (the “Final Terms”) which, with respect to Notes to be listed, will be filed with the Central Bank. Copies of Final Terms in relation to Notes to be listed on Euronext Dublin’s Official List will also be published on Euronext Dublin’s website (www.ise.ie). The Programme provides that Notes may be listed or admitted to trading, as the case may be, on such other or further stock exchanges or markets as may be agreed between the Issuer and the relevant Dealer. The Issuer may also issue unlisted Notes and/or Notes not admitted to trading on any market. The Issuer may agree with any Dealer and the Trustee (as defined herein) that Notes may be issued in a form not contemplated by the Terms and Conditions of the Notes herein, in which event, a new Base Prospectus or a drawdown prospectus, in the case of listed Notes only, if appropriate, will be made available which will describe the effect of the agreement reached in relation to such Notes. Tranches or Series of Notes to be issued under the Programme will be rated or unrated. Where a Tranche or Series of Notes is to be rated, such rating will not necessarily be the same as the rating assigned to the Issuer or to Notes already issued. Where a Tranche or Series of Notes is rated, the applicable rating(s) may be specified in the relevant Final Terms. Whether or not each credit rating applied for in relation to relevant Series of Notes will be issued by a credit rating agency established in the European Union and registered under Regulation (EC) No.1060/2009 (as amended) (the “CRA Regulation”), and included in the list of credit rating agencies published by the European Securities and Markets Authority on its website (at http://www.esma.europa.eu/page/List-registered-and-certified-CRAs) in accordance with the CRA Regulation, will be disclosed in the applicable Final Terms. A security rating is not a recommendation to buy, sell or hold securities and may be subject to suspension, reduction or withdrawal at any time by the assigning rating agency. Please also refer to “Risks related to the market generally” in the “Risk Factors” section of this Base Prospectus. Amounts payable under the Notes may be calculated by reference, inter alia, to EURIBOR, which is provided by the European Money Markets Institute, or to LIBOR, which is provided by ICE Benchmark Administration Limited, as specified in the relevant Final Terms. As at the date of this Base Prospectus, the European Money Markets Institute does not appear on the register of administrators and benchmarks established and maintained by the European Securities and Markets Authority (“ESMA”) pursuant to Article 36 of Regulation (EU) 2016/1011 (the “Benchmarks Regulation”). As far as the Issuer is aware, the transitional provisions in Article 51 of the Benchmarks Regulation apply, such that the European Money Markets Institute is not currently required to obtain authorisation or registration (or, if located outside the European Union, recognition, endorsement or equivalence). As at the date of this Base Prospectus, ICE Benchmark Administration Limited appears on the register of administrators and benchmarks established and maintained by ESMA pursuant to the Benchmarks Regulation. Arrangers BNP PARIBAS UniCredit Bank Dealers Banca IMI Barclays BNP PARIBAS BofA Merrill Lynch Crédit Agricole CIB Goldman Sachs International J.P. Morgan Mediobanca Morgan Stanley NATIXIS Société Générale Corporate & Investment Banking UniCredit Bank The date of this Base Prospectus is 5 July 2018. 2 NOTICE TO INVESTORS This Base Prospectus comprises a base prospectus in respect of all Notes issued under the Programme for the purposes of Article 5.4 of the Prospectus Directive. The Issuer accepts responsibility for the information contained in this Base Prospectus and the Final Terms for each Tranche of Notes issued under the Programme. To the best of the knowledge of the Issuer (having taken all reasonable care to ensure that such is the case) the information contained in this Base Prospectus is in accordance with the facts and does not omit anything likely to affect the import of such information. Copies of Final Terms will be available from the registered office of the Issuer and the specified office set out below of each of the Paying Agents (as defined under “Terms and Conditions of the Notes”). In relation to Notes to be listed on Euronext Dublin’s Official List, Final Terms will also be published on the website of Euronext Dublin (www.ise.ie). This Base Prospectus is to be read in conjunction with all documents which are deemed to be incorporated herein by reference (see “Documents Incorporated by Reference”). This Base Prospectus shall be read and construed on the basis that such documents are incorporated by reference and form part of this Base Prospectus. No representation, warranty or undertaking, express or implied, is made and no responsibility or liability is accepted by the Dealers or their respective affiliates or Deutsche Trustee Company Limited (the “Trustee”) as to the accuracy or completeness of the information contained or incorporated by reference in this Base Prospectus or any other information provided by the Issuer in connection with the Programme. None of the Dealers and the Trustee accepts any liability in relation to the information contained or incorporated by reference in this Base Prospectus or any other information provided by the Issuer in connection with the Programme. No person is or has been authorised by the Issuer, any of the Dealer or the Trustee to give any information or to make any representation not contained in or not consistent with this Base Prospectus or any other information supplied in connection with the Programme or the Notes and, if given or made, such information or representation must not be relied upon as having been authorised by the Issuer or any of the Dealers or the Trustee. Neither this Base Prospectus nor any other information supplied in connection with the Programme or any Notes (i) is intended to provide the basis of any credit or other evaluation or (ii) should be considered as a recommendation by the Issuer, any of the Dealers or the Trustee that any recipient of this Base Prospectus or any other information supplied in connection with the Programme or any Notes should purchase any Notes.