Okeanis Eco Tankers Corp美股招股说明书(2026-01-20版)

OKEANIS ECO TANKERS CORP. We are offeringof our shares of common stock, $0.001 par value per share, or our common shares, directly toseveral investors pursuant to this prospectus supplement and the accompanying prospectus. This prospectus supplement and the accompanying prospectus may be made available in electronic format on websites orthrough other online services maintained by the placement agents or by their affiliates. Other than this prospectus supplementand the accompanying prospectus, the information on the placement agents’ websites and any information contained in anyother website maintained by the placement agents is not part of this prospectus supplement and the accompanying prospectusor the registration statement of which this prospectus supplement and the accompanying prospectus form a part, has not beenapproved and/or endorsed by us or the placement agents, and should not be relied upon by investors. The common shares of Okeanis Eco Tankers Corp., or the Company, are listed on the New York Stock Exchange, or theNYSE, under the symbol “ECO” and on the Oslo Stock Exchange, under the symbol “OET.” On January 16, 2026, the lastsale price of our common shares as reported on the NYSE was $39.56 per common share. An investment in our common shares involves risks. See the section entitled “Risk Factors” beginning on pageS-9of thisprospectus supplement and page5of the accompanying prospectus and in the documents incorporated by reference herein andtherein, including our annual report onForm 20-F for the year ended December31, 2024 filed with the Securities and ExchangeCommission on March31, 2025, or our Annual Report, to read about the risks you should consider before purchasing oursecurities. We have retained Fearnley Securities AS, Clarksons Securities AS and Pareto Securities AS (whom we refer to herein asthe Placement Agents) as our exclusive placement agents in connection with this offering. The Placement Agents are notpurchasing or selling any of our common shares offered pursuant to this prospectus supplement and the accompanyingprospectus, and have no commitment to buy any of the shares. See “Plan of Distribution” beginning on pageS-19of thisprospectus supplement for more information regarding these arrangements. We expect that delivery of our common shares being offered pursuant to this prospectus supplement will be made to theinvestors on or about, 2026, subject to customary closing conditions. The following table shows per common share and total cash Placement Agent’s fees we expect to pay to the PlacementAgents in connection with the sale of the securities pursuant to this prospectus supplement and the accompanying prospectus,assuming the sale and purchase of all of the securities offered hereby to non-affiliates of the Company, and assuming that wedo not pay any discretionary amount to the Placement Agents: Per ShareTotalPublic offering price$$Placement Agent’s fees$$Proceeds, before expenses, to the Company$$(1) We have agreed to pay the Placement Agents a cash fee equal to 3.75% of the gross proceeds of the offering except forany purchases by certain of our affiliates. We have agreed that we may also pay up to an additional 0.75% of the grossproceeds of the offering, except for any purchases by certain of our affiliates, entirely in our discretion. In addition, wehave agreed to pay certain expenses of the Placement Agents, as discussed under “Plan of Distribution.” We have alsoagreed to provide indemnification and contribution to the Placement Agent with respect to certain liabilities, includingcertain liabilities under the Securities Act of 1933, as amended. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Anyrepresentation to the contrary is a criminal offense. Joint Global Coordinators Fearnley Securities AS Clarksons Securities AS Joint BookrunnersThe information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are part of aneffective registration statement filed with the Securities and Exchange Commission under the Securities Act of 1933, as amended. This preliminary prospectus supplement is not an offer tosell securities, and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted. The date of this prospectus supplement is , 2026 TABLE OF CONTENTS PROSPECTUS SUPPLEMENT PageABOUT THIS PROSPECTUS SUPPLEMENTS-iiCAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTSS-ivPROSPECTUS SUPPLEMENT SUMMARYS-1THE OFFERINGS-7RISK FACTORSS-9USE OF PROCEEDSS-14CAPITALIZATIONS-15DILUTIONS-16DESCRIPTION OF SECURITIES WE ARE OFFERINGS-17TAX CONSIDERATIONSS-18PLAN OF DISTRIBUTIONS-19ENFORCEABILITY OF CIVIL LIABILITIESS-23EXPENSESS-24LEGAL MATT