Okeanis Eco Tankers Corp. – New Shares Issued and Commencement of Trading

Reference is made to the stock exchange release by Okeanis Eco Tankers Corp. (the “Company”, OSE ticker code: “OET”, NYSE ticker code: “ECO”) on 21 January 2026 regarding the successful offering of 3,611,111 new common shares (the “Offer Shares”) of the Company at a price of USD 36.00 per Offer Share, raising gross proceeds of approximately USD 130 million (the “Offering”).

The Company has issued the Offer Shares in The Depository Trust Company (the “DTC“) in the United States and such shares will be available for trading on the New York Stock Exchange on or around 23 January 2026. The Offer Shares may also be transferred from DTC to Euronext Securities Oslo (the “VPS“) in accordance with the customary arrangements for transfers of the Company’s common shares between DTC and VPS and be traded on Euronext Oslo Børs.

Following issuance of the Offer Shares, the Company has 39,740,547 common shares issued, of which 39,044,655 common shares are deemed outstanding (there are 695,892 common shares held in treasury), each with a par value of USD 0.001.

Fearnley Securities AS and Clarksons Securities AS have acted as joint global coordinators and joint bookrunners, and Pareto Securities AS has acted as joint bookrunner for the Offering (collectively referred to as the “Managers”). Advokatfirmaet BAHR AS acted as Norwegian legal counsel, and Watson Farley & Williams LLP acted as US legal counsel, to the Company. Advokatfirmaet Thommessen AS acted as Norwegian legal counsel, and Seward & Kissel LLP acted as US legal counsel, to the Managers.

The Offer Shares were sold pursuant to a shelf registration statement on Form F-3 (File No. 333- 287032), previously filed with the Securities and Exchange Commission (the “SEC”) on 7 May 2025 and declared effective on 21 May 2025. The Offering was made only by means of a prospectus, including a prospectus supplement prepared specifically in relation to the Offering and filed under Rule 424(b) under the U.S. Securities Act of 1933, forming a part of the effective registration statement. A final prospectus supplement and accompanying prospectus relating to the securities described above were filed with the SEC on 21 January 2026. Copies of the prospectus supplement and the accompanying prospectus relating to Offering may be obtained at www.sec.gov. A written prospectus may also be obtained by contacting Fearnley Securities AS at Αυτή η διεύθυνση ηλεκτρονικού ταχυδρομείου προστατεύεται από τους αυτοματισμούς αποστολέων ανεπιθύμητων μηνυμάτων. Χρειάζεται να ενεργοποιήσετε τη JavaScript για να μπορέσετε να τη δείτε., Clarksons Securities AS at Αυτή η διεύθυνση ηλεκτρονικού ταχυδρομείου προστατεύεται από τους αυτοματισμούς αποστολέων ανεπιθύμητων μηνυμάτων. Χρειάζεται να ενεργοποιήσετε τη JavaScript για να μπορέσετε να τη δείτε. or Pareto Securities AS Αυτή η διεύθυνση ηλεκτρονικού ταχυδρομείου προστατεύεται από τους αυτοματισμούς αποστολέων ανεπιθύμητων μηνυμάτων. Χρειάζεται να ενεργοποιήσετε τη JavaScript για να μπορέσετε να τη δείτε..