SCHEDULE: Imperial Petroleum's C3is Stake Reaches 68.8% After Offering

Imperial Petroleum Inc. updated its beneficial ownership in C3is Inc. to 68.8% of common stock following a registered offering and warrant exercises by C3is Inc.

Summary

• Imperial Petroleum Inc. now beneficially owns 6,000,000 shares of C3is Inc. Common Stock.
• This represents 68.8% of C3is Inc.'s outstanding Common Stock.
• The beneficial ownership percentage was updated due to changes in the conversion price of C3is Inc.'s 5.0% Series A Cumulative Convertible Perpetual Preferred Stock.
• The conversion price for the Series A Convertible Preferred Stock has been adjusted to $2.50 per share.
• The adjustment resulted from C3is Inc.'s sale of Common Stock in a registered offering, as detailed in a prospectus supplement filed on October 9, 2025.
• The percentage ownership also reflects dilution from the revised total number of outstanding Common Stock shares, including those issued in the registered offering and upon exercise of outstanding warrants.
• Harry N. Vafias, Chairman, CEO, and President of Imperial Petroleum, also serves as Non-Executive Chairman of C3is Inc. and beneficially owns 100,577 shares of C3is Inc. Common Stock.

Sentiment

Score: 6

Explanation: The filing indicates Imperial Petroleum maintains a strong controlling stake in C3is Inc. and outlines a flexible strategy for its investment, which is generally positive for the reporting entity. The dilution for C3is Inc. shareholders is a consequence of C3is Inc.'s capital raise, not a direct action by Imperial Petroleum that would negatively impact its own position.

Positives

• Imperial Petroleum Inc. maintains a significant controlling interest of 68.8% in C3is Inc.
• The conversion price adjustment for the Series A Convertible Preferred Stock to $2.50 clarifies the terms for Imperial Petroleum's potential conversion.

Negatives

• Existing C3is Inc. common shareholders experienced dilution in their percentage ownership due to the registered offering and warrant exercises.

Risks

• Imperial Petroleum may acquire additional securities, or retain or sell all or a portion of its shares in C3is Inc. at any time.
• Imperial Petroleum may engage in discussions with C3is Inc. management and other shareholders regarding operations, business conduct, and potential extraordinary corporate transactions.
• Imperial Petroleum reserves the right to change its intentions or formulate new plans regarding its investment in C3is Inc.

Future Outlook

Imperial Petroleum intends to continuously review its investment in C3is Inc. and may, at its discretion, acquire additional securities, or retain or sell its current holdings. Future actions will depend on an ongoing evaluation of C3is Inc.'s business, financial condition, market conditions, and strategic alternatives.

Management Comments

• Imperial Petroleum intends to review its investment in C3is Inc. on a continuing basis.
• Imperial Petroleum may from time to time acquire additional securities of C3is Inc., or retain or sell all or portion of the shares then held.
• Imperial Petroleum may engage in discussions with C3is Inc. management and other relevant parties, which may include matters ranging from operations and business conduct to considering or exploring extraordinary corporate transactions.

Industry Context

This filing reflects a common practice among holding companies or strategic investors to update their ownership stakes in subsidiaries or investee companies, particularly following capital market activities such as registered offerings or warrant exercises by the investee. The significant ownership percentage indicates a controlling interest, typical in a parent-subsidiary or closely affiliated corporate structure within the shipping industry.

Related Party Transactions

• Harry N. Vafias serves as Chairman, Chief Executive Officer, and President of Imperial Petroleum and as Non-Executive Chairman of C3is Inc.
• John Kostoyannis and George Xiradakis are directors of both Imperial Petroleum and C3is Inc.
• Imperial Petroleum's significant beneficial ownership (68.8%) in C3is Inc. establishes a controlling relationship.

Stakeholder Impact

• Shareholders (C3is Inc.): Experienced dilution in their percentage ownership due to the registered offering and warrant exercises.
• Shareholders (Imperial Petroleum): The filing confirms Imperial Petroleum's continued significant influence and control over C3is Inc.
• Management (C3is Inc.): The overlap in board members and executive roles between Imperial Petroleum and C3is Inc. suggests close strategic alignment and potential influence from Imperial Petroleum.

Next Steps

• Imperial Petroleum will continue to review its investment in C3is Inc.
• Imperial Petroleum may acquire or sell C3is Inc. securities based on ongoing evaluations.
• Imperial Petroleum may engage in discussions with C3is Inc. management and other parties regarding business operations and potential corporate transactions.

Key Dates

Keywords

Imperial Petroleum, C3is Inc., Schedule 13D, Beneficial Ownership, Common Stock, Preferred Stock, Convertible Securities, Dilution, Registered Offering, Corporate Governance, Shipping Industry