U.S. Offer to Purchase (i) Outstanding Common Stock, without par value, held by U.S. Persons and (ii) Outstanding American Depositary Shares (each American Depositary Share representing 30 shares of Common Stock) of ENEL GENERACIÓN CHILE S.A. (“Enel Generación”) for Cash by ENEL CHILE S.A. (“Enel Chile”) Subject to the terms and conditions described in this prospectus, including the Enel Chile U.S. Share/ADS Subscription Condition (as defined herein) THE OFFER PERIOD COMMENCED ON FEBRUARY 16, 2018 AND WILL EXPIRE AT 4:30 P.M., NEW YORK CITY TIME (THE “EXPIRATION TIME”), ON MARCH 22, 2018 (THE “EXPIRATION DATE”), UNLESS THE U.S. OFFER IS EXTENDED. Eligible Security Corresponding Consideration per Eligible Security Common stock, without par value, of Enel Ch$590 in cash, without interest, payable in U.S. Generación (“Enel Generación Shares”) dollars to be delivered net of applicable withholding taxes and distribution fees, subject to the Enel Chile ISIN: CLP3710M1090 U.S. Share/ADS Subscription Condition American depositary shares, each representing 30 Ch$17,700 in cash, without interest, payable in U.S. shares of Enel Generación common stock (“Enel dollars to be delivered net of applicable withholding Generación ADSs”) taxes, subject to the Enel Chile U.S. Share/ADS Subscription Condition ISIN: US29244T1016 CUSIP: 29244T101 Enel Chile S.A., a publicly held stock corporation (sociedad anónima abierta) organized under the laws of the Republic of Chile, hereby offers to purchase (i) all outstanding shares of common stock, without par value, of Enel Generación Chile S.A., a publicly held stock corporation (sociedad anónima abierta) organized under the laws of the Republic of Chile, other than Enel Generación Shares currently owned by Enel Chile, held by all U.S. Persons (as defined herein) for an amount of Ch$590 in cash, without interest, payable in U.S. dollars, net of applicable withholding taxes and distribution fees for each Enel Generación Share; and (ii) all outstanding American Depositary Shares of Enel Generación (together with Enel Generación Shares, “Enel Generación Securities”), from all holders of Enel Generación ADSs, wherever located, for an amount of Ch$17,700 in cash, without interest, payable in U.S. dollars, net of applicable withholding taxes for each Enel Generación ADS, in each case upon the terms and subject to certain conditions described in this prospectus (including the Enel Chile U.S. Share/ADS Subscription Condition as defined below) and in the Form of Acceptance, the ADS Letter of Transmittal and the Subscription Agreement (which together, as they may be amended or supplemented from time to time, constitute the “U.S. Offer”). The U.S. Offer is subject to the condition that any eligible holder of Enel Generación Shares and/or Enel Generación ADSs validly tendering Enel Generación Shares and/or Enel Generación ADSs in the U.S. Offer shall have agreed to apply Ch$236 of the consideration payable for each Enel Generación Share validly tendered (the “Enel Chile Share Subscription Amount”) and Ch$7,080 of the consideration payable for each Enel Generación ADS validly tendered to subscribe for shares of common stock, without par value, of Enel Chile (“Enel Chile Shares”) or American Depositary Shares, each representing 50 Enel Chile Shares (each an “Enel Chile ADS” and together with the Enel Chile Shares, the “Enel Chile Securities”), as the case may be, at a subscription price of Ch$82 per Enel Chile Share (or Ch$4,100 per Enel Chile ADS) (the “Enel Chile U.S. Share/ ADS Subscription Condition”). Following completion of the U.S. Offer, for each Enel Generación Share validly tendered in the U.S. Offer, an Enel Generación shareholder will receive Ch$354 in cash, without interest, payable in U.S. dollars net of applicable withholding taxes and distribution fees, and 2.87807 Enel Chile Shares as a result of its satisfaction of the Enel Chile U.S. Share/ADS Subscription Condition. Following completion of the U.S. Offer, for each Enel Generación ADS validly tendered in the U.S. Offer, an Enel Generación ADS holder will receive Ch$10,620 in cash, without interest, payable in U.S. dollars net of applicable withholding taxes, and 1.72683 Enel Chile ADSs (subject to a US$0.05 issuance fee for each Enel Chile ADS) as a result of its satisfaction of the Enel Chile U.S. Share/ADS Subscription Condition. The aggregate Enel Chile Share Subscription Amount of all Enel Generacio´n Shares validly tendered by each Enel Generacio´n shareholder will be used to purchase the largest whole number of Enel Chile Shares that can be purchased with such amount and any remaining portion of the Enel Chile Share Subscription Amount will be delivered in cash together with the cash portion of the consideration in the Offers. This prospectus relates to the Enel Chile Shares (including Enel Chile Shares underlying the Enel Chile ADSs) to be subscribed by holders of Enel Generación Shares and Enel Generación ADSs tendering their Enel Generación Shares and/ or Enel Generación ADSs in the U.S. Offer pursuant to the Enel Chile U.S. Share/ADS Subscription Condition. Through a concurrent offer in Chile, Enel Chile is offering to purchase any and all of the outstanding Enel Generación Shares, other than Enel Generación Shares currently owned by Enel Chile but including Enel Generación Shares held by U.S. Persons (the “Chilean Offer”), at the purchase price of Ch$590 in cash for each Enel Generación Share. The Chilean Offer is subject to the condition that any eligible holder of Enel Generación Shares tendering in the Chilean Offer shall have agreed to apply Ch$236 of the consideration payable for each Enel Generación Share tendered to subscribe for Enel Chile Shares at a subscription price of Ch$82 per Enel Chile Share (the “Enel Chile Share Subscription Condition”). As a result, following completion of the Chilean Offer, for each Enel Generación Share validly tendered, an Enel Generación shareholder will receive Ch$354 in cash and 2.87807 Enel Chile Shares as a result of its satisfaction of the Enel Chile Share Subscription Condition. The U.S. Offer and the Chilean Offer are being conducted simultaneously and, in all material respects, have the same terms and are subject to the same conditions; however, participants in the Chilean Offer (including U.S. Persons), may not be granted the protection of the U.S. Securities Exchange Act of 1934, as amended. The Chilean Offer and the U.S. Offer are collectively referred to as the “Offers.” Under Chilean law, the initial offering period of the Chilean Offer must be 30 calendar days and may be extended one time for a period of between 5 to 15 calendar days. The initial 30-day offering period of the Chilean Offer was scheduled to expire on March 17, 2018; however, Enel Chile has extended the Chilean Offer offering period by 5 days to March 22, 2018, in accordance with Chilean law, to coincide with the expiration of the initial U.S. Offer period. The Chilean Offer may not be further extended beyond March 22, 2018, even if the U.S. Offer is extended. For a discussion of the risk factors that you should consider in evaluating the U.S. Offer, see “Risk Factors” beginning on page 43. Neither the Securities and Exchange Commission nor any foreign or state securities commission has approved or disapproved of the securities to be issued under this prospectus, nor passed upon the merits or fairness of the securities to be issued under this prospectus, nor determined if this prospectus is accurate or adequate. Any representation to the contrary is a criminal offense. Enel Chile and Enel Chile Shares have been registered with the Comisio´n para el Mercado Financiero (the Chilean Financial Market Commission, formerly known as the Superintendencia de Valores y Seguros, or the “SVS”). The SVS has not approved or disapproved of the securities offered hereby (including in the form of ADSs) or determined if this prospectus or any Spanish language prospectus that will be used in Chile is truthful or complete. This prospectus and the related documents contain important information. You should carefully read these documents in their entirety before making a decision with respect to the U.S. Offer. Dealer Manager for the U.S. Offer BTG PACTUAL This prospectus is dated February 8, 2018 and is expected first to be mailed to Enel Generación shareholders on or about February 16, 2018. IMPORTANT We are not making the U.S. Offer to, and will not accept any tendered Enel Generación Shares or Enel Generación ADSs from or on behalf of Enel Generación Share or Enel Generación ADS holders residing in any jurisdiction in which the making of the U.S. Offer or acceptance thereof would not be in compliance with the laws of that jurisdiction. However, we may, at our discretion, take any actions necessary for us to make the U.S. Offer to Enel Generación Share or Enel Generación ADS holders in any such jurisdiction. Tenders by Holders of Enel Generación Shares: Any holder of Enel Generación Shares that is a U.S. Person desiring to tender all or any portion of the Enel Generación Shares owned by such holder in the U.S. Offer must: (i) complete and sign the Form of Acceptance (or a copy thereof, provided the signature is original) in accordance with the instructions in the Form of Acceptance and mail or deliver it to Computershare Trust Company N.A., as U.S. tender agent of Enel Chile for the Enel Generación Shares in the U.S. Offer (the “U.S.