0001193125-25-235146 Sample Contracts

SECURITIES PURCHASE AGREEMENT
Securities Purchase Agreement • October 9th, 2025 • C3is Inc. • Deep sea foreign transportation of freight • New York

This Securities Purchase Agreement (this “Agreement”) is dated as of October 8, 2025, between C3is Inc., a Republic of Marshall Islands corporation (the “Company”), and each purchaser identified on the signature pages hereto (including their respective successors and assigns, each a “Purchaser” and collectively, the “Purchasers”).

Re: CISS | Registered Direct Offering | Placement Agent Agreement
Placement Agent Agreement • October 9th, 2025 • C3is Inc. • Deep sea foreign transportation of freight • New York

The purpose of this placement agent agreement is to outline our agreement pursuant to which Aegis Capital Corp. (“Aegis”) will act as the placement agent on a “best efforts” basis in connection with the proposed Registered Direct Shelf Takedown (the “Placement”) by C3is Inc. (collectively, with its subsidiaries and affiliates, the “Company”) of its shares of Common Stock (the “Securities”). This placement agent agreement sets forth certain conditions and assumptions upon which the Placement is premised. The Company expressly acknowledges and agrees that Aegis’s obligations hereunder are on a reasonable “best efforts” basis only and that the execution of this Agreement does not constitute a commitment by Aegis to purchase the Securities and does not ensure the successful placement of the Securities or any portion thereof or the success of Aegis with respect to securing any other financing on behalf of the Company. The Company confirms that entry into this placement agent agreement and c