DESCRIPTION OF SHARE CAPITAL

We were incorporated as an exempted company limited by shares under the Companies Act. Accordingly, the rights of our shareholders are governed by Bermuda law and our memorandum of association and bye-laws. Our authorized share capital (capital stock) is 500,000,000 common shares par value $1.00 per share and 30,000,000 preferred shares par value $1.00 per share. No preferred shares are currently outstanding.

Preferred Shares

We may issue preferred shares in one or more series, as described below. The following briefly summarizes the provisions of our bye-laws that would be important to holders of our preferred shares. The following description may not be complete and you should refer to our amended and restated memorandum of association and bye-laws, any applicable certificate of designation, preferences and rights or similar document, and any applicable resolution of our board of directors for complete information regarding the terms of the class or series of preferred shares described in a prospectus supplement.

The description of most of the financial and other specific terms of your series will be in the prospectus supplement accompanying this prospectus. Those terms may vary from the terms described here. As you read this section, please remember that the specific terms of your series of preferred shares as described in your prospectus supplement will supplement and, if applicable, may modify or replace the general terms described in this section. If there are differences between your prospectus supplement and this prospectus, your prospectus supplement will control. Thus, the statements we make in this section may not apply to your series of preferred shares.

Reference to a series of preferred shares means all of the preferred shares issued as part of the same series under a certificate of designations filed as part of our restated articles of incorporation. Reference to your prospectus supplement means the prospectus supplement describing the specific terms of the preferred shares you purchase. The terms used in your prospectus supplement will have the meanings described in this prospectus, unless otherwise specified.

Our Authorized Preferred Shares

Our board of directors is empowered, without approval of our stockholders, to cause the preferred shares to be issued in one or more series, with the numbers of shares of each series and the powers, preferences and rights, and qualifications, limitations or restrictions of the series to be determined by it.

The prospectus supplement relating to the particular series of preferred shares will contain a description of the specific terms of that series as fixed by our board of directors, including, as applicable:

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When we issue and receive payment for preferred shares, the shares will be fully paid and nonassessable, which means that its holders will have paid their purchase price in full and that we may not ask them to pay additional funds. Unless otherwise specified in the prospectus supplement relating to a particular series of preferred shares, each series of preferred shares will rank on a parity in all respects with each other series of preferred shares and prior to our common shares as to dividends and any distribution of our assets.

The rights of holders of the preferred shares offered may be adversely affected by the rights of holders of any other preferred shares that may be issued in the future. Our board of directors may cause preferred shares to be issued in public or private transactions for any proper corporate purposes and may include issuances to obtain additional financing in connection with acquisitions, and issuances to officers, directors and employees pursuant to benefit plans. Our board of directors’ ability to issue preferred shares may discourage attempts by others to acquire control of us without negotiation with our board of directors, as it may make it difficult for a person to acquire us without negotiating with our board of directors.

Common Shares

Subject to any preferred shares created by our board of directors, each outstanding common share is entitled to such dividends as our board of directors may declare from time to time out of funds that we can legally use to pay dividends.

Subject to the adjustment regarding voting set forth in “Voting Adjustments” below, each holder of our common shares is entitled to one vote for each common share and does not have any right to cumulate votes in the election of directors. In the event of our liquidation, dissolution or winding-up, holders of our common shares will be entitled to receive on a pro-rata basis any assets remaining after provision for payment of creditors and after payment of any liquidation preferences to holders of preferred shares. Holders of our common shares are not entitled to preemptive, redemption, or sinking fund rights. When we issue and receive payment for common shares, the shares will be fully paid and nonassessable, which means that its holders will have paid their purchase price in full and that we may not ask them to surrender additional funds.

As of September 14, 2012, we had 25,162,086 outstanding common shares.

The transfer agent and registrar for our common shares is American Stock Transfer & Trust Company.

Our common shares are listed on the NASDAQ Global Select Market under the symbol “AGII.” The common shares currently issued and outstanding are fully paid and non-assessable.

Certain Provisions of Our Bye-laws

The following summarizes some of the important provisions of our bye-laws. Because this summary is necessarily brief and cannot contain all of the provisions and conditions contained in our bye-laws, you should refer to our bye-laws for complete information, including the definitions of some of the terms used below. Copies

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of our bye-laws are incorporated by reference as exhibits to the registration statement of which this prospectus forms a part. The following summary is qualified in its entirety by such reference.

Voting Adjustments

Under our bye-laws, the voting power of all shares is automatically adjusted to the extent necessary so that there is no 9.5% U.S. Member (as defined below), provided that no one Member (as defined below) owns greater than 75% of the voting power of the issued shares of the Company determined without applying the following voting power adjustments or eliminations. Our board of directors shall from time to time, including prior to any time at which a vote of Members is taken, take all reasonable steps necessary to ascertain, through communications with Members or otherwise, whether there exists, or will exist at the time any vote of Members is taken, a Tentative 9.5% U.S. Member (as defined below). In the event that a Tentative 9.5% U.S. Member exists, the aggregate votes conferred by shares held by a Member and treated as Controlled Shares (as defined below) of that Tentative 9.5% U.S. Member shall be reduced to the extent necessary such that the Controlled Shares of the Tentative 9.5% U.S. Member will constitute less than 9.5% of the voting power of all issued and outstanding shares. In applying the previous sentence where shares held by more than one Member are treated as Controlled Shares of such Tentative 9.5% U.S. Member, the reduction in votes shall apply to such Members in descending order according to their respective Attribution Percentages (as defined below), provided that, in the event of a tie, the reduction shall apply pro rata to such Members. The votes of Members owning no shares treated as Controlled Shares of any Tentative 9.5% U.S. Member shall, in the aggregate, be increased by the same number of votes subject to reduction as described above provided however that no shares shall be conferred votes to the extent that doing so will cause any person to be treated as a 9.5% U.S. Member. Such increase shall be apportioned to all such Members in proportion to their voting power at that time, provided that such increase shall be limited to the extent necessary to avoid causing any person to be a 9.5% U.S. Member.

The adjustments of voting power described above shall apply repeatedly until there would be no 9.5% U.S. Member. Our board of directors may deviate from any of the principles described above and determine that shares held by a Member shall carry different voting rights as it determines appropriate (1) to avoid the existence of any 9.5% U.S. Member or (2) to avoid adverse tax, legal or regulatory consequences to us, any of our subsidiaries, or any direct or indirect shareholder or its affiliates.

In addition, our board of directors may adjust a shareholder’s voting rights to the extent that our board of directors determines that it is necessary in order to avoid adverse tax, legal or regulatory consequences to the Company, any subsidiary of the Company, or any other direct or indirect holder of shares or its affiliates, provided that no adjustment pursuant to this sentence shall cause any person to become a 9.5% U.S. Member.

“Attribution Percentage” means, with respect to a Member, the percentage of the Member’s shares that are treated as Controlled Shares of a Tentative 9.5% U.S. Member.

“Controlled Shares” means all shares of the Company directly, indirectly or constructively owned by a person as determined pursuant to sections 957 and 958 of the Internal Revenue Code of 1986, as amended, of the United States (the “Code”), and the Treasury Regulations promulgated thereunder.

“Member” means a duly registered holder from time to time of the shares in the capital of the Company.

“9.5% U.S. Member” means a U.S. Person whose Controlled Shares constitute nine and one half percent (9.5%) or more of the voting power of all issued shares of the Company and who generally would be required to recognize income with respect to the Company under section 951(a)(1) of the Code, if the Company were a controlled foreign corporation as defined in section 957 of the Code and if the ownership threshold under section 951(b) of the Code were 9.5%.

“Tentative 9.5% U.S. Member” means a U.S. person that, but for adjustments or restrictions on exercise of the voting power of shares as described above, would be a 9.5% U.S. Member.

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Our board of directors also has the authority under our bye-laws to request from any direct or indirect shareholder such information as may be reasonably requested for the purpose of determining whether any holder’s voting rights are to be adjusted pursuant to the bye-laws. If a shareholder fails to respond to such a request or submits incomplete or inaccurate information in response to such a request, our board of directors, in its sole discretion, may determine that such holder’s shares shall carry no voting rights until otherwise determined by our board of directors.

Restrictions on Transfer

Our bye-laws provide that if our board of directors determines that share ownership by any shareholder may result in any non-de minimis adverse tax, regulatory or legal consequences to the Company, any subsidiary of the Company, or any direct or indirect holder of shares or its affiliates, then it may decline to approve or register or permit the registration of such transfer of shares. In addition, our board of directors may in its absolute discretion decline to register a transfer of any share to more than four joint holders.

In addition, each transfer must comply with current BMA permission or have specific permission from the BMA. Transfers must be by instrument unless otherwise permitted by the Companies Act.

If our board of directors refuses to register a transfer in accordance with our bye-laws, it shall send written notice to the proposed transferor and transferee within 120 days after the date on which the transfer was delivered to the Company. The bye-laws also provide that our board of directors may suspend the registration of transfers at such time and for such periods as our board of directors may determine, provided that they may not suspend the registration of transfers for more than 30 days in any year.

Anti-Takeover Effects of Bye-laws

Provisions of our bye-laws may delay or make more expensive or difficult unsolicited acquisitions or changes of our control. These provisions may also have the effect of making it more difficult for third parties to cause the replacement of our board of directors or current management without their agreement. We believe that these provisions will enable us to develop our business in a manner that will foster long-term growth without disruption caused by the threat of a takeover not thought by our board of directors to be in our best interests and the best interests of our stockholders.

Our bye-laws provide that our board of directors shall consist of not less than three nor more than thirteen directors, as determined by the Company by ordinary resolution, divided into three approximately equal classes (Class I, Class II, and Class III). Our board of directors currently is comprised of three class I directors whose term will expire at our 2014 annual general meeting, three class II directors whose term will expire at our 2015 annual general meeting and four class III directors whose term will expire at our 2013 annual general meeting. Nominations to our board of directors other than those made by our board of directors must be delivered to or mailed and received at the Company not less than 60 days prior to a general meeting of our shareholders. Directors may be removed, with or without cause, prior to the expiration of such director’s term at a meeting of shareholders, provided that such director is given notice before the meeting and is given the opportunity to be heard at such meeting. The appointment or removal of a director requires the simple majority of votes entitled to vote thereon, represented in person or by proxy, at the general meeting at which the proposal is put forth. A special general meeting of shareholders may be convened by our board of directors or at the request of shareholders holding at the date of the delivery of the written notice of not less than 10% of the paid-up voting share capital of Argo Group.

As described above, any U.S. person owning, directly, indirectly or by attribution, more than 9.5% of our common shares will have the voting rights attached to such common shares reduced so that it may not exercise more than 9.5% of the total voting rights.

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As described above, our board of directors also may decline to register the transfer of any shares if it believes that the transfer may expose us, any subsidiary of the Company, or any direct or indirect holder of shares or its affiliates to non-de minimis adverse tax, legal, or regulatory treatment or if any share is be to transferred to more than four joint holders. A transferor of our shares will be deemed to own the shares until the name of the transferee is entered on our register of members.

Subject to any resolution of our shareholders to the contrary, our board of directors shall have the power to appoint any person as a director to fill a casual vacancy on our board of directors, provided that the number of directors so appointed shall not exceed any maximum number determined by our shareholders in a general meeting of our shareholders and may also fill any vacancy caused by the removal of a director by our shareholders, provided that our shareholders have not elected or appointed any director at the meeting at which the director was removed or passed a resolution to the contrary.

Any amendment to our bye-laws or our memorandum of association shall be approved by our board of directors and decided on by an ordinary resolution of our shareholders.

Restrictions on Ownership Under Insurance Laws

The application of various insurance laws in the jurisdictions in which our insurance subsidiaries are incorporated or commercially domiciled will be a significant deterrent to any person interested in acquiring control. The insurance holding company laws of each of the jurisdictions in which our insurance subsidiaries are incorporated or commercially domiciled, as well as state corporation laws, govern any acquisition of control of our insurance subsidiaries or of us. In general, these laws provide that no person or entity may directly or indirectly acquire control of an insurance company unless that person or entity has received the prior approval of the insurance regulatory authorities. An acquisition of control would be presumed in the case of any person or entity who purchases 10% or more of our outstanding common shares, unless the applicable insurance regulatory authorities determine otherwise.

As noted, pursuant to the Insurance Act, a shareholder or prospective shareholder is responsible for notifying the BMA in writing of his becoming a shareholder controller, directly or indirectly, of 10%, 20%, 33% or 50% of Argo Group and ultimately its Bermudian insurance subsidiary, Argo Re Ltd. (“Argo Re”), within 45 days of becoming such a shareholder controller. Argo Re is also required to notify the BMA in the event of any person becoming or ceasing to be a controller (being a managing director, chief executive or other person in accordance with whose directions or instructions the directors of Argo Re are accustomed to act, including any person who holds, or is entitled to exercise, 10% or more of the voting shares or voting power or is able to exercise a significant influence over the management of Argo Re) or officer of the company. The BMA may serve a notice of objection on any controller of Argo Re if it appears to the BMA that the person is no longer fit and proper to be such a controller.

Differences in Corporate Law

The Companies Act, which applies to us, differs in certain material respects from laws generally applicable to corporations formed under U.S. state laws and their shareholders. Set forth below is a summary of certain significant provisions of the Companies Act (including modifications adopted pursuant to our bye-laws) applicable to us that differ in certain respects from provisions of Delaware corporate law. Because the following statements are summaries, they do not purport to deal with all aspects of Bermuda law that may be relevant to us and our shareholders.

Interested Directors. Bermuda law provides that if a director has a personal interest in a transaction to which the company is also a party and if the director discloses the nature of this personal interest at the first opportunity, either at a meeting of directors or in writing to the directors, then the company will not be able to declare the transaction void solely due to the existence of that personal interest and the director will not be liable to the

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company for any profit realized from the transaction. In addition, under Bermuda law, after a director has made the declaration of interest referred to above, he is allowed to be counted for purposes of determining whether a quorum is present and to vote on a transaction in which he has an interest, unless disqualified from doing so by the chairman of the relevant board meeting. Under Delaware law such transaction would not be voidable if (1) the material facts as to such interested director’s relationship or interests are disclosed to or are known by the board of directors and the board in good faith authorizes the transaction by the affirmative vote of a majority of the disinterested directors, (2) such material facts are disclosed to or are known by the stockholders entitled to vote on such transaction and the transaction is specifically approved in good faith by vote of the majority of shares entitled to vote thereon or (3) the transaction is fair as to the corporation as of the time it is authorized, approved or ratified. Under Delaware law, such interested director could be held liable for a transaction in which such director derived an improper personal benefit.

Mergers and Similar Arrangements. The amalgamation or merger of a Bermuda company with another company or corporation (other than certain affiliated companies) requires the amalgamation or merger agreement to be approved by the company’s board of directors and by its shareholders. We may, with the approval of a majority of the then outstanding shares entitled to vote on such matter, amalgamate or merger with another Bermuda company or with a body incorporated outside Bermuda. In the case of an amalgamation or merger, a shareholder may apply to a Bermuda court for a proper valuation of such shareholder’s shares if such shareholder is not satisfied that fair value has been paid for such shares. Under Delaware law, with certain exceptions, a merger, consolidation or sale of all or substantially all the assets of a corporation must be approved by the board of directors and a majority of the outstanding shares entitled to vote thereon. Under Delaware law, a stockholder of a corporation participating in certain major corporate transactions may, under certain circumstances, be entitled to appraisal rights pursuant to which such stockholder may receive cash in the amount of the fair value of the shares held by such stockholder (as determined by a court) in lieu of the consideration such stockholder would otherwise receive in the transaction.

Takeovers. Bermuda law provides that where an offer is made for shares of a company and, within four months of the offer, the holders of not less than 90% of the shares which are the subject of the offer accept, the offeror may by notice require the non-tendering shareholders to transfer their shares on the terms of the offer. Dissenting shareholders may apply to the court within one month of the notice objecting to the transfer. The test is one of fairness to the body of the shareholders and not to individuals and the burden is on the dissenting shareholder to prove unfairness, not merely that the scheme is open to criticism. Delaware law provides that a parent corporation, by resolution of its board of directors and without any stockholder vote, may merge with any subsidiary of which it owns at least 90% of each class of capital stock. Upon any such merger, dissenting stockholders of the subsidiary would have appraisal rights.

Shareholders’ Suits. The rights of shareholders under Bermuda law are not as extensive as the rights of shareholders under legislation or judicial precedent in many U.S. jurisdictions. Class actions and derivative actions are generally not available to shareholders under the laws of Bermuda. However, the Bermuda courts ordinarily would be expected to follow English case law precedent, which would permit a shareholder to commence an action in the name of the company to remedy a wrong done to the company where the act complained of is alleged to be beyond the corporate power of the company or is illegal or would result in the violation of our memorandum of association or bye-laws. Furthermore, consideration would be given by the court to acts that are alleged to constitute a fraud against the minority shareholders or where an act requires the approval of a greater percentage of our shareholders than actually approved it. The winning party in such an action generally would be able to recover a portion of attorneys’ fees incurred in connection with such action. Our bye-laws provide that shareholders waive all claims or rights of action that they might have, individually or by or in the right of the Company, against any director or officer for any act or failure to act in the performance of such director’s or officer’s duties, or supposed duties, with or for Argo Group, except that such waiver shall not extend to any matter in respect of any fraud or dishonesty which may attach to such director or officer. Class actions and derivative actions generally are available to stockholders under Delaware law for, among other things, breach of fiduciary duty, corporate waste and actions not taken in accordance with applicable law. In such

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actions, the court has discretion to permit the winning party to recover attorneys’ fees incurred in connection with such action.

Indemnification of Directors and Officers. Pursuant to our bye-laws (which are governed by Bermuda law), we shall indemnify our directors and officers against all actions, costs, charges, losses, damages and expenses incurred or sustained by such person by reason of any act done, concurred in or omitted in or about the execution of their duty, or supposed duty, or in their respective offices or trusts; provided that such indemnification shall not extend to any matter in respect of any fraud or dishonesty which may attach to such director or officer. Under Delaware law, a corporation may indemnify a director or officer of the corporation against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred in defense of an action, suit or proceeding by reason of such position if (i) such director or officer acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation and, (ii) with respect to any criminal action or proceeding, such director or officer had no reasonable cause to believe his or her conduct was unlawful.

Inspection of Corporate Records. Members of the general public have the right to inspect our public documents at the office of the Registrar of Companies in Bermuda, which will include our memorandum of association (including its objects and powers) and any alteration to our memorandum of association and documents relating to any increase or reduction of authorized capital. Our shareholders have the additional right to inspect our bye-laws, minutes of general meetings and audited financial statements, which must be presented at the annual general meeting of shareholders. The register of our shareholders is also open to inspection by shareholders and members of the public without charge. We are required to maintain our share register in Bermuda but may establish a branch register outside Bermuda. We are required to keep at our registered office a register of our directors and officers, which is open for inspection by members of the public without charge. Bermuda law does not, however, provide a general right for shareholders to inspect or obtain copies of any other corporate records. Delaware law permits any stockholder to inspect or obtain copies of a corporation’s stockholder list and its other books and records for any purpose reasonably related to such person’s interest as a stockholder.

DESCRIPTION OF ARGO GROUP DEBT SECURITIES

The following description of the debt securities sets forth certain general terms and provisions of such debt securities to which this prospectus and any prospectus supplement may relate, and such description does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all the provisions of the indentures, including the supplemental indentures or officers’ certificates to be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part. The particular terms of any series of debt securities and the extent to which the general provisions may apply to a particular series of debt securities will be described in a prospectus supplement relating to that series. We may issue senior debt securities or subordinated debt securities under indentures with a trustee to be chosen by us and qualified to act under the Trust Indenture Act of 1939, as amended. In addition, we may issue junior subordinated debt securities to the Capital Trust in connection with the issuance of trust preferred securities and common securities by the Capital Trust.

The material provisions of the indentures are summarized below. The summary is not complete. Our senior debt securities are to be issued under an indenture (the “Argo Group senior indenture”), the form of which is filed as an exhibit to this registration statement of which this prospectus forms a part. Our subordinated debt securities are to be issued under an indenture (the “Argo Group subordinated indenture”), the form of which is filed as an exhibit to this registration statement of which this prospectus forms a part. The senior indenture and the subordinated indenture are sometimes referred to herein, collectively, as the “Argo Group indentures” and each, individually, as an “Argo Group indenture.” You should read the Argo Group indentures for provisions that may

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be important to you. In this section, references to “we” refer only to Argo Group International Holdings, Ltd. and not to any of its subsidiaries unless the context otherwise requires.

Because we have included only a summary of the material indenture terms, you must read the Argo Group indentures (including any supplemental indenture or officers’ certificate filed with respect thereto) in full to understand every detail of the terms of the debt securities.

General

We may issue debt securities from time to time in one or more series without limitation as to aggregate principal amount. The senior debt securities will be unsecured and unsubordinated obligations and will rank equally and ratably with our other unsecured and unsubordinated obligations. The subordinated debt securities will be unsecured obligations and will be subordinated in right of payment, as set forth in the subordinated indenture, to the prior payment in full of our existing and future senior indebtedness.

Unless otherwise indicated in the prospectus supplement, principal of, premium, if any, and interest on the debt securities will be payable, and the transfer of debt securities will be registrable, at any office or agency maintained by us for that purpose. Unless otherwise indicated in the applicable prospectus supplement, the debt securities will be issued only in denominations of $1,000 or integral multiples thereof. No service charge will be made for any registration of transfer or exchange of the debt securities, but we may require you to pay a sum sufficient to cover any tax or other governmental charge imposed in connection with the transfer or exchange.

We will prepare a prospectus supplement for each series of debt securities that it issues. Each prospectus supplement will set forth the applicable terms of the debt securities to which it relates. These terms will include some or all of the following:

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We may offer and sell the debt securities as original issue discount securities at a substantial discount below their stated principal amount. The prospectus supplement will describe the U.S. federal income tax consequences

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and other special considerations applicable to original issue discount securities and any debt securities the federal tax laws treat as having been issued with original issue discount. “Original issue discount securities” means any debt security which provides for an amount less than its principal amount to be due and payable upon the declaration of acceleration of the maturity of the debt security upon the occurrence and continuation of an event of default.

The indenture does not contain covenants or other provisions designed to afford holders of the debt securities protection in the event of a highly leveraged transaction, change in credit rating or other similar occurrence.

The above is not intended to be an exclusive list of the terms that may be applicable to any debt securities and we are not limited in any respect in our ability to issue debt securities with terms different from or in addition to those described above or elsewhere in this prospectus, provided that the terms are not inconsistent with the indenture.

Global Debt Securities

Notes may be issued in the form of one or more fully registered global securities which will be deposited with, or on behalf of, The Depository Trust Company, New York, New York (the “Depositary” or “DTC”) and registered in the name of Cede & Co., the Depositary’s nominee. Beneficial interests in the global securities may be represented through book-entry accounts of financial institutions acting on behalf of beneficial owners as direct and indirect participants in the Depositary.

Investors may elect to hold interests in the global securities through the Depositary, if they are participants in such systems, or indirectly through organizations which are participants in such systems. Except as described below, the global securities may be transferred, in whole and not in part, only to another nominee of the Depositary or to a successor of the Depositary or its nominee.

So long as the Depositary or its nominee is the registered owner of the global securities, the Depositary or its nominee, as the case may be, will be considered the sole owner or holder of the notes represented by the global securities for all purposes under the indenture. Except as provided below, owners of beneficial interests in the global securities will not be entitled to have notes represented by the global securities registered in their names, will not receive or be entitled to receive physical delivery of notes in definitive form, and will not be considered the owners or holders thereof under the indenture.

Principal and interest payments on notes registered in the name of the Depositary or its nominee will be made to the Depositary or its nominee, as the case may be, as the registered owner of the global securities. None of Argo Group, the trustee, any paying agent, or registrar for the notes will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial interests in the global securities or for maintaining, supervising, or reviewing any records relating to those beneficial interests.

We expect that the Depositary or its nominee, upon receipt of any payment of principal or interest, will credit the participants’ accounts with payments in amounts proportionate to their respective beneficial interests in the principal amount of the global securities as shown on the records of the Depositary or its nominee. We also expect that payments by participants to owners of beneficial interests in the global securities held through these participants will be governed by standing instructions and customary practices, as is now the case with securities held for the accounts of customers in bearer form or registered in “street name.” The participants are responsible for the standing instructions and customary practices governing beneficial interests.

The Depositary and the direct and indirect participants will send notices and communications to direct and indirect participants and beneficial owners, as the case may be, in accordance with the arrangements governing their relationships, subject to any statutory or regulatory requirements as may be in effect from time to time.

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DTC has provided us the following information: DTC is a limited-purpose trust company organized under the laws of the State of New York, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code and a “clearing agency” registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934. DTC holds and provides asset servicing for U.S. and non-U.S. equity, corporate and municipal debt issues and money market instruments that DTC’s participants, referred to as “direct DTC participants,” deposit with DTC. DTC also facilitates the post-trade settlement among direct participants of sales and other securities transactions in deposited securities through electronic computerized book-entry transfers and pledges between direct participants’ accounts, thereby eliminating the need for physical movement of certificates. Direct DTC participants include both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation, which is owned, in part, by a number of direct DTC participants. Indirect access to the DTC system is also available to others, referred to as “indirect DTC participants,” for example, securities brokers and dealers, banks, trust companies and clearing corporations, that clear through or maintain a custodial relationship with a direct DTC participant, either directly or indirectly. DTC rules applicable to direct and indirect participants are on file with the SEC.

Beneficial interests in a global security will be shown on, and transfers of beneficial interests in the global security will be made only through, records maintained by DTC and its participants, both direct and indirect. When you purchase debt securities through the DTC system, the purchases must be made by or through a direct DTC participant, which will receive credit for the debt securities in its account on DTC’s records. When you actually purchase the debt securities, you will become their beneficial owner. Your ownership interest will be recorded only on the direct or indirect DTC participants’ records. DTC will have no knowledge of your individual ownership of the debt securities. DTC’s records will show only the identity of the direct DTC participants and the amount of the debt securities held by or through them. You will not receive a written confirmation of your purchase or sale or any periodic account statement directly from DTC. You should instead receive these confirmations and account statements from the direct or indirect DTC participant through which you purchase the debt securities. The direct or indirect DTC participants are responsible for keeping accurate account of the holdings of their customers. The trustee will wire payments on the debt securities to the DTC nominee that is the registered holder of the debt securities. The trustee and we will treat DTC or its nominee as the owner of each global security for all purposes. Accordingly, the trustee, any paying agent, and we will have no direct responsibility or liability to pay amounts due on a global security to you or any other beneficial owners in that global security. Any redemption notices will be sent by us directly to DTC, which will, in turn, inform the direct or indirect DTC participants, which will then contact you as a beneficial holder.

Under the rules, regulations and procedures creating and affecting DTC and its operations, DTC is required to make book-entry transfers between direct DTC participants on whose behalf it acts with respect to the debt securities and is required to receive and transmit distributions of principal of and premium, if any, and interest on the debt securities. Direct and indirect DTC participants with which investors have accounts with respect to the debt securities similarly are required to make book-entry transfers and receive and transmit payments on behalf of their respective investors.

As DTC can only act on behalf of direct DTC participants, who in turn act on behalf of indirect DTC participants and certain banks, the ability of a person having a beneficial interest in a security held in DTC to transfer or pledge that interest to persons or entities that do not participate in the DTC system, or otherwise take actions in respect of that interest, may be affected by the lack of a physical certificate representing that interest. The laws of some states of the United States require that certain persons take physical delivery of securities in definitive form in order to transfer or perfect a security interest in those securities. Consequently, the ability to transfer beneficial interests in a security held in DTC to those persons may be limited.

DTC has advised us that it will take any action permitted to be taken by a holder of debt securities under the terms and conditions of the debt securities (including, without limitation, the presentation of debt securities for

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exchange) only at the direction of one or more of the direct DTC participants to whose accounts with DTC interests in the relevant debt securities are credited, and only in respect of the portion of the aggregate principal amount of the debt securities as to which that direct DTC participant or those direct DTC participants has or have given the direction. However, in certain circumstances described below, DTC will exchange the global securities held by it for certificated debt securities, which it will distribute to the direct DTC participants.

It is DTC’s current practice, upon receipt of any payment of distributions or liquidation amounts, to proportionately credit direct DTC participants’ accounts on the payment date based on their holdings of the relevant securities. In addition, it is DTC’s current practice to pass through any consenting or voting rights to such direct DTC participants by using an omnibus proxy. Consequently, those direct DTC participants should, in turn, make payments to and solicit votes from you, the ultimate owner of debt securities, based on their customary practices. Payments to you with respect to your beneficial interest in any debt securities will be the responsibility of the direct and indirect DTC participants and not of DTC, the trustee or us.

Individual certificates in respect of the notes will be issued in exchange for the global securities only if:

In the event that individual certificates are issued, holders of the notes will be able to receive payments (including principal and interest) on the notes and effect transfer of the notes at the offices of our paying agent.

Title to book-entry interests in the notes will pass by book-entry registration of the transfer within the records of DTC in accordance with their respective procedures. Book-entry interests in the notes may be transferred within DTC in accordance with procedures established for this purpose by DTC.

The information in this section concerning DTC and DTC’s book-entry system has been obtained from sources that we believe to be reliable, but we take no responsibility for the accuracy thereof. Furthermore, DTC has no obligation to perform or continue to perform the procedures described above, and may discontinue or change those procedures at any time.

Events of Default

With respect to a series of debt securities, any one of the following events will constitute an event of default under the indenture:

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If any event of default occurs and continues, either the trustee or the holders of at least 25 percent in aggregate principal amount of the outstanding debt securities of that series may declare the principal amount of all the debt securities of that series or, if the debt securities of that series are original issue discount securities, the portion of the principal amount as may be specified in the terms of those debt securities, to be due and payable immediately by a notice in writing to us, and to the trustee if given by holders. The principal amount (or specified amount) will then be immediately due and payable. If an event of default occurs involving our bankruptcy, insolvency or reorganization, the principal amount of all outstanding securities under the indenture will be due and payable immediately without any action on the part of the trustee or the holders. After acceleration, but before a judgment or decree based on acceleration has been obtained, the holders of a majority in aggregate principal amount of outstanding debt securities of that series may, under certain circumstances, rescind and annul the acceleration.

The prospectus supplement relating to any series of debt securities that are original issue discount securities will contain the particular provisions relating to acceleration of the stated maturity of a portion of the principal amount of that series of original issue discount securities upon the occurrence and continuation of an event of default.

Each indenture provides that, subject to the duty of the trustee during default to act with the required standard of care, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request or direction of any of the holders, unless the holders offer the trustee reasonable indemnity. Generally, the holders of a majority in aggregate principal amount of the debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee.

A holder of any series of debt securities will not have any right to institute any proceeding with respect to the indenture, or for the appointment of a receiver or trustee, or for any other remedy, unless:

However, these limitations do not apply to a suit instituted by a holder for enforcement of payment of the principal of and premium, if any, or interest on their debt security on or after the respective due dates.

We are required to furnish to the trustee annually a statement as to our performance of certain obligations under the applicable indenture and as to any default.

Modification and Waiver

We and the indenture trustee may, subject to obtaining any required consents with respect thereto, change or supplement an indenture without the consent of any holders with respect to certain matters, including:

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In addition, under the indentures, we and the indenture trustee may add, change or eliminate any provisions of the indentures with the consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected, provided that the following actions require the consent of each holder affected:

The holders of not less than a majority in aggregate principal amount of the outstanding debt securities of any series may, on behalf of all holders of that series, waive any past default under the indenture, except a default in respect of a covenant or provision of the indenture that cannot be modified or amended without the consent of those holders of each outstanding debt security of that series who were affected.

Payment of Additional Amounts

Unless otherwise described in a prospectus supplement, if any taxes, assessments or other governmental charges are imposed by the jurisdiction, other than the United States, where we or any of our respective successors (a “payor”), is organized or otherwise considered to be a resident for tax purposes, any jurisdiction, other than the United States, from or through which the payor makes a payment on the debt securities, or, in each case, any political organization or governmental authority thereof or therein having the power to tax (the “relevant tax jurisdiction”) in respect of any payments under the debt securities, the payor will pay to each holder of the debt securities, to the extent it may lawfully do so, such additional amounts as may be necessary in order that the net amounts paid to such holder will be not less than the amount specified in such debt securities to which such holder is entitled; provided, however, the payor will not be required to make any payment of additional amounts for or on account of:

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nor will additional amounts be paid with respect to any payment of the principal of, or any premium or interest on, any notes to any holder who is a fiduciary or partnership or limited liability company or other than the sole beneficial owner of such payment to the extent such payment would be required by the laws of the relevant tax jurisdiction to be included in the income for tax purposes of a beneficiary or settlor with respect to such fiduciary or a member of such partnership or limited liability company or beneficial owner who would not have been entitled to such additional amounts had it been the holder of such notes.

Redemption for Tax Purposes

Unless otherwise described in a prospectus supplement, we may redeem the debt securities at our option, in whole but not in part, at a redemption price equal to 100% of the principal amount, together with accrued and unpaid interest and additional amounts, if any, to the date fixed for redemption, at any time we receive an opinion of counsel that as a result of (1) any change in or amendment to the laws or treaties (or any regulations or rulings promulgated under these laws or treaties) of Bermuda or any taxing jurisdiction (or of any political subdivision or taxation authority affecting taxation) or any change in the application or official interpretation of such laws, regulations or rulings, (2) any action taken by a taxing authority of Bermuda or any taxing jurisdiction (or any political subdivision or taxing authority affecting taxation) which action is generally applied or is taken with respect to us, or (3) a decision rendered by a court of competent jurisdiction in Bermuda or any taxing jurisdiction (or any political subdivision) whether or not such decision was rendered with respect to us, there is a substantial probability that we will be required as of the next interest payment date to pay additional amounts with respect to the debt securities as provided in “—Payment of Additional Amounts” above and such requirements cannot be avoided by the use of reasonable measures (consistent with practices and interpretations generally followed or in effect at the time such measures could be taken) then available. If we elect to redeem the debt securities under this provision, we will give written notice of such election to the trustee and the holders of the debt securities. Interest on the debt securities will cease to accrue unless we default in the payment of the redemption price.

Consolidation, Merger and Sale of Assets

We may not consolidate with, merge into or amalgamate with any other company or entity or sell, assign, transfer, lease or otherwise convey all or substantially all its assets to another company or entity, unless:

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Defeasance and Covenant Defeasance

The indenture provides, unless otherwise indicated in the prospectus supplement relating to that particular series of debt securities, that, at our option, we:

in each case, if we deposit, in trust, with the trustee money or U.S. government obligations, which through the payment of interest and principal in accordance with their terms will provide money, in an amount sufficient to pay all the principal of and premium, if any, and interest on the debt securities of that series on the dates such payments are due, which may include one or more redemption dates that we designate, in accordance with the terms of the debt securities of that series

We may establish this trust only if, among other things:

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If we fail to comply with our remaining obligations under the indenture after a defeasance of the indenture with respect to the debt securities of any series as described under the second item of the preceding sentence and the debt securities of such series are declared due and payable because of the occurrence of any event of default, the amount of money and U.S. government obligations on deposit with the trustee may be insufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. We will, however, remain liable for those payments.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the laws of the State of New York.

Certain Covenants of Argo Group

Unless otherwise specified in the prospectus supplement, the following covenant will apply to the senior debt securities issued by us.

Limitation on Liens. We shall not, and shall not permit any of our restricted subsidiaries to, issue, assume, incur or enter into a guarantee of, any indebtedness for borrowed money secured by a mortgage, pledge, lien, encumbrance or other security interest, directly or indirectly, upon any voting shares of a restricted subsidiary which are now owned or hereafter acquired by us or our subsidiaries without effectively providing concurrently that the senior debt securities (and if we so elect, any other indebtedness of ours ranking on a parity with the senior debt securities) shall be secured equally and ratably with, or prior to, any such secured indebtedness so long as such indebtedness remains outstanding. This restriction shall not apply to permitted liens.

The following are the meanings of terms that are important in understanding the restrictive covenant described above:

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Subordination of Subordinated Debt Securities

The subordinated debt securities of each series will, to the extent set forth in the subordinated indenture, be subordinate in right of payment to the prior payment in full of all senior indebtedness with respect to such series. Upon any payment or distribution of the assets of any kind or character, whether in cash, property or securities, to creditors upon any dissolution, winding-up, liquidation or reorganization, whether voluntary or involuntary, or in bankruptcy, insolvency, receivership or other proceedings, all amounts due upon all senior indebtedness with respect to the subordinated debt securities of any series will first be paid in full, or payment thereof provided for in money in accordance with its terms, before the holders of subordinated debt securities of such series are entitled to receive or retain any payment on account of principal of, or any premium or interest on, or any additional amounts with respect to, the subordinated debt securities of such series, and to that end the holders of such senior indebtedness shall be entitled to receive, for application to the payment thereof, any payment or distribution of any kind or character, whether in cash, property or securities, including any such payment or distribution which may be payable or deliverable by reason of the payment of any other indebtedness of ours being subordinated to the payment of subordinated debt securities of such series, which may be payable or deliverable in respect of the subordinated debt securities of such series upon any such dissolution, winding-up, liquidation or reorganization or in any such bankruptcy, insolvency, receivership or other proceeding.

By reason of such subordination, in the event of liquidation or insolvency, holders of senior indebtedness with respect to the subordinated debt securities of any series and holders of other obligations that are not subordinated to such senior indebtedness may recover more ratably than the holders of the subordinated debt securities of such series.

Subject to the payment in full of all senior indebtedness with respect to the subordinated debt securities of any series, the rights of the holders of the subordinated debt securities of such series will be subrogated to the rights of the holders of such senior indebtedness to receive payments or distributions of cash, property or securities of ours applicable to such senior indebtedness until the principal of, any premium and interest on, and any additional amounts with respect to, the senior indebtedness with respect to the subordinated debt securities of such series have been paid in full.

No payment of principal (including redemption and sinking fund payments) of or any premium or interest on or any additional amounts with respect to the subordinated debt securities of any series may be made by us (1) if any senior indebtedness with respect to such series is not paid when due and any applicable grace period with respect to such default has ended and such default has not been cured or waived or ceased to exist, or (2) if the maturity of any senior indebtedness with respect to such series has been accelerated because of a default.

The subordinated indenture does not limit or prohibit us from incurring additional senior indebtedness, which may include indebtedness that is senior to the subordinated debt securities of any series, but subordinate to our other obligations. The senior debt securities will constitute senior indebtedness with respect to the subordinated debt securities of each series under the subordinated indenture.

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Under the subordinated indenture, “senior indebtedness” includes all of our obligations to pay principal, premium and interest:

The following types of indebtedness will not rank senior to the subordinated debt securities:

The subordinated indenture provides that the foregoing subordination provisions, insofar as they relate to any particular series of subordinated debt securities, may be changed prior to such issuance. Any such change would be described in the related prospectus supplement.

DESCRIPTION OF WARRANTS

Debt Warrants

We may issue, together with other securities or separately, warrants for the purchase of debt securities (“debt warrants”). The debt warrants are to be issued under debt warrant agreements (each a “debt warrant agreement”) to be entered into between us and a bank or trust company, as debt warrant agent (the “debt warrant agent”), all as set forth in the applicable prospectus supplement. The debt warrant agent will act solely as our agent in connection with the debt warrants of such series and will not assume any obligations or relationship of agency or trust for or with any holders or beneficial owners of debt warrants. Copies of the forms of debt warrant agreements and the forms of warrant certificates (the “debt warrant certificates”) will be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part. The following description of certain provisions of the forms of debt warrant agreements and debt warrant certificates does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all the provisions of the debt warrant agreements and the debt warrant certificates to be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part.

General

You should look in the applicable prospectus supplement for the following terms of the offered debt warrants:

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Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations and debt warrants may be exercised at the corporate trust office of the debt warrant agent or any other office indicated in the applicable prospectus supplement. Before the exercise of their debt warrants, holders of debt warrants will not have any of the rights of holders of the debt securities purchasable upon such exercise and will not be entitled to payments of principal, premium, if any, or interest, if any, on the debt securities purchasable upon such exercise.

Exercise of Debt Warrants

Each debt warrant will entitle the holder to purchase the principal amount of debt securities at the exercise price determinable in the applicable prospectus supplement. Debt warrants may be exercised at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business of the expiration date, unexercised debt warrants will become void.

Debt warrants may be exercised as set forth in the applicable prospectus supplement relating to the debt warrants. Upon receipt of payment and the debt warrant certificate properly completed and duly executed at the

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corporate trust office of the debt warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the debt securities purchasable upon such exercise. If less than all of the debt warrants represented by the debt warrant certificate are exercised, a new debt warrant certificate will be issued for the remaining amount of debt warrants.

Stock Warrants

We may issue, together with other securities or separately, warrants for the purchase of common shares or preferred shares (“stock warrants”). The stock warrants are to be issued under stock warrant agreements (each a “stock warrant agreement”) to be entered into between us and a bank or trust company, as stock warrant agent (the “stock warrant agent”), all as set forth in the applicable prospectus supplement. The stock warrant agent will act solely as our agent in connection with the stock warrants of such series and will not assume any obligations or relationship of agency or trust for or with any holders or beneficial owners of stock warrants. Copies of the forms of stock warrant agreements and the forms of warrant certificates (the “stock warrant certificates”) will be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part. The following description of certain provisions of the forms of stock warrant agreements and stock warrant certificates does not purport to be complete and is subject to, and are qualified in their entirety by reference to, all the provisions of the stock warrant agreements and the stock warrant certificates to be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part.

General

If we offer warrants for the purchase of common shares and/or preferred shares, the applicable prospectus supplement will describe their terms, which may include the following:

The common shares or preferred shares issuable upon the exercise of the stock warrants will, when issued in accordance with the stock warrant agreement, be fully paid and nonassessable.

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Prior to the exercise of their stock warrants, holders of stock warrants will not have any of the rights of holders of the common shares or preferred shares purchasable upon such exercise, and will not be entitled to any dividend payments on the common shares or preferred shares purchasable upon such exercise.

Exercise of Stock Warrants

Each stock warrant will entitle the holder to purchase for cash the number of common shares or preferred shares at the exercise price as shall in each case be set forth in, or be determinable as set forth in, the applicable prospectus supplement. Unless otherwise specified in the applicable prospectus supplement, stock warrants may be exercised at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised stock warrants will become void.

Stock warrants may be exercised as set forth in the applicable prospectus supplement. Upon receipt of payment and the stock warrant certificates properly completed and duly executed at the corporate trust office of the stock warrant agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward a certificate representing the number of common shares or preferred shares purchasable upon such exercise. The applicable prospectus supplement may provide for net settlement of share warrants whereby the cash payment due upon exercise of the warrants will be deemed paid through adjustment of the number of shares to be issued upon exercise of the warrants. If less than all of the stock warrants represented by the stock warrant certificate are exercised, a new stock warrant certificate will be issued for the remaining amount of stock warrants.

No fractional shares will be issued upon exercise of stock warrants, but we will pay the cash value of any fractional shares otherwise issuable.

The exercise price payable and the number of common shares or preferred shares purchasable upon the exercise of each stock warrant and the number of stock warrants outstanding will be subject to adjustment in certain events, including the issuance of a stock dividend to holders of common shares or preferred shares, respectively, or a combination, subdivision or reclassification of common shares or preferred shares, respectively. In lieu of adjusting the number of common shares or preferred shares purchasable upon exercise of each stock warrant, we may elect to adjust the number of stock warrants. No adjustment in the number of shares purchasable upon exercise of the stock warrants may be required until cumulative adjustments require an adjustment of at least 1% thereof.

DESCRIPTION OF UNITS

We may, from time to time, issue units comprised of one or more of the other securities that may be offered under this prospectus, in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately at any time, or at any time before a specified date.

Any applicable prospectus supplement will describe:

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DESCRIPTION OF DEPOSITARY SHARES

The following description of the depositary shares sets forth the material terms and provisions of the depositary shares to which any prospectus supplement may relate. You should read the particular terms of any depositary shares and any depositary receipts that are offered by us, and any deposit agreement relating to a particular series of common shares or preferred shares, which will be described in more detail in an applicable prospectus supplement, which will also include a discussion of certain U.S. federal income tax considerations. The applicable prospectus supplement will also state whether any of the general provisions summarized below do not apply to the depositary shares being offered.

General

We may issue depositary shares that represent common shares or preferred shares. The common shares or preferred shares represented by depositary shares will be deposited under a deposit agreement between us and a bank or trust company selected by us and having its principal office in the United States and combined capital and surplus of at least $50 million. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, in proportion to the applicable common shares or preferred shares or fraction thereof represented by the depositary share, to all of the rights and preferences of the common shares or preferred shares represented thereby, including any dividend, voting, redemption, conversion and liquidation rights. The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement.

We may, at our option, elect to offer fractional shares of common shares or preferred shares, rather than full common shares or preferred shares. In the event we exercise this option, we will issue receipts for depositary shares, each of which will represent a fraction, to be described in an applicable prospectus supplement, of a common share or a share of a particular series of common shares or preferred shares as described below.

Pending the preparation of definitive depositary receipts, the depositary may, upon our written order or the written order of any holder of deposited common shares or preferred shares, execute and deliver temporary depositary receipts that are substantially identical to, and that entitle the holders to all the rights pertaining to, the definitive depositary receipts. Depositary receipts will be prepared thereafter without unreasonable delay, and temporary depositary receipts will be exchangeable for definitive depositary receipts at our expense.

Dividends and Other Distributions

The depositary will distribute all cash dividends and other cash distributions received in respect of the deposited common shares or preferred shares to the record holders of depositary shares relating to the common shares or preferred shares, in proportion to the numbers of the depositary shares owned by such holders.

In the event of a non-cash distribution, the depositary will distribute property it receives to the appropriate record holders of depositary shares. If the depositary determines that it is not feasible to make a distribution, it may, with our approval, sell the property and distribute the net proceeds from the sale to the holders.

Redemption of Shares

Subject to Bermuda law, if a series of common shares or preferred shares represented by depositary shares is to be redeemed, the depositary shares will be redeemed from the proceeds received by the depositary resulting from the redemption, in whole or in part, of each series of common shares or preferred shares held by the depositary. The depositary shares will be redeemed by the depositary at a price per depositary share equal to the applicable fraction of the redemption price per share payable in respect of the common shares or preferred shares so redeemed. Whenever we redeem common shares or preferred shares held by the depositary, the depositary will redeem, as of the same date, the number of depositary shares representing common shares or preferred shares redeemed. If fewer than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by the depositary by lot or pro rata or by any other equitable method as may be determined by the depositary.

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Withdrawal of Shares

Any holder of depositary shares may, upon surrender of the depositary receipts at the corporate trust office of the depositary, unless the related depositary shares have previously been called for redemption, receive the number of whole shares of the related series of common shares or preferred shares and any money or other property represented by the depositary receipts. Holders of depositary shares making withdrawals will be entitled to receive whole shares of common shares or preferred shares on the basis described in an applicable prospectus supplement for such series of common shares or preferred shares, but holders of whole common shares or preferred shares will not thereafter be entitled to deposit the common shares or preferred shares under the deposit agreement or to receive depositary receipts therefor. If the depositary shares surrendered by the holder in connection with a withdrawal exceed the number of depositary shares that represent the number of whole common shares or preferred shares to be withdrawn, the depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares.

Voting Deposited Common Shares or Preferred Shares

Upon receipt of notice of any meeting at which the holders of any series of deposited common shares or preferred shares are entitled to vote, the depositary will mail the information contained in the notice of meeting to the record holders of the depositary shares relating to such series of common shares or preferred shares. Each record holder of the depositary shares on the record date, which will be the same date as the record date for the relevant series of common shares or preferred shares, will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the amount of the common shares or preferred shares represented by the holder’s depositary shares.

The depositary will attempt, insofar as practicable, to vote the amount of such series of common shares or preferred shares represented by the depositary shares in accordance with the instructions, and we will agree to take all reasonable actions that may be deemed necessary by the depositary to enable the depositary to do so. The depositary will refrain from voting the common shares or preferred shares to the extent it does not receive specific instructions from the holder of depositary shares representing the common shares or preferred shares.

Amendment and Termination of the Deposit Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the depositary. However, any amendment that materially and adversely alters the rights of the holders of the depositary shares representing common shares or preferred shares of any series will not be effective unless the amendment has been approved by the holders of at least the amount of the depositary shares then outstanding representing the minimum amount of common shares or preferred shares of such series necessary to approve any amendment that would materially and adversely affect the rights of the holders of the common shares or preferred shares of such series. Every holder of an outstanding depositary receipt at the time any amendment becomes effective, or any transferee of the holder, will be deemed, by continuing to hold the depositary receipt, or by reason of the acquisition thereof, to consent and agree to the amendment and to be bound by the deposit agreement as amended thereby. The deposit agreement will automatically terminate if:

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay all charges of the depositary in connection with the initial deposit of the

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relevant series of common shares or preferred shares and any redemption of the common shares or preferred shares. Holders of depositary receipts will pay other transfer and other taxes and governmental charges and other charges or expenses as are expressly provided in the deposit agreement.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering to us notice of its election to do so, and we may at any time remove the depositary, any resignation or removal to take effect upon the appointment of a successor depositary and its acceptance of the appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50 million.

Miscellaneous

The depositary will forward all reports and communications from us that are delivered to the depositary and that we are required to furnish to the holders of the deposited common shares or preferred shares.

Neither we nor the depositary will be liable if we are or it is prevented or delayed by law or any circumstances beyond our or its control in performing any obligations under the deposit agreement. Our and their obligations under the deposit agreement will be limited to performance in good faith of our and their duties under the deposit agreement and neither we nor they will be obligated to prosecute or defend any legal proceeding in respect of any depositary shares, depositary receipts, common shares or preferred shares unless satisfactory indemnity is furnished. The depositary may rely upon written advice of counsel or accountants, or upon information provided by holders of depositary receipts or other persons believed to be competent and on documents believed to be genuine.

PURCHASE CONTRACTS

We may issue share purchase contracts representing contracts obligating holders to purchase from us, and us to sell to the holders, a specified or varying number of our common shares, preferred shares or depositary shares at a future date or dates. Alternatively, the share purchase contracts may obligate us to purchase from holders, and obligate holders to sell to us, a specified or varying number of common shares, preferred shares or depositary shares. The number and price per share of our common shares, preferred shares or depositary shares may be fixed at the time the share purchase contracts are entered into or may be determined by reference to a specific formula set forth in the share purchase contracts. The share purchase contracts may be entered into separately or as a part of a share purchase unit that consists of (a) a share purchase contract; (b) warrants; and/or (c) debt securities, trust preferred securities or debt obligations of third parties (including U.S. treasury securities, other share purchase contracts or common shares), that would secure the holders’ obligations to purchase or to sell, as the case may be, common shares, preferred shares or depositary shares under the share purchase contract. The share purchase contracts may require us to make periodic payments to the holders of the share purchase units or vice-versa. These payments may be unsecured or prefunded and may be paid on a current or on a deferred basis. The share purchase contracts may require holders to secure their obligations under the contracts in a specified manner.

The applicable prospectus supplement will describe the terms of any share purchase contract or share purchase unit and will contain a discussion of certain U.S. federal income tax considerations and special considerations applicable to the share purchase contracts and share purchase units. The description in the applicable prospectus supplement will not necessarily be complete, and reference will be made to the share purchase contracts, and, if applicable, collateral or depositary arrangements, relating to the share purchase contracts or share purchase units.

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DESCRIPTION OF TRUST PREFERRED SECURITIES AND TRUST GUARANTEES

Trust Preferred Securities

The restated declaration, which will be restated prior to the issuance of any securities of the trust, will authorize the trustees of the Capital Trust to issue on behalf of the Capital Trust one series of trust preferred securities and one series of trust common securities. We collectively refer to the trust preferred securities and the trust common securities as the trust securities. The trust preferred securities will be issued to the public pursuant to the registration statement of which this prospectus is a part, and the trust common securities will be issued directly or indirectly to us.

The trust preferred securities will have the terms, including dividends, redemption, voting, conversion, liquidation rights and other preferred, deferred or other special rights or restrictions as are described in the restated declaration or made part of the restated declaration by the Trust Indenture Act.

You should refer to the applicable prospectus supplement relating to the trust preferred securities of each Capital Trust for specific terms, including:

Pursuant to the restated declaration, the institutional trustee will own our debt securities purchased by the Capital Trust for the benefit of the trust preferred securities holders and the trust common securities holders. The payment of dividends out of money held by the Capital Trust, and payments upon redemption of trust preferred securities or liquidation of the Capital Trust, will be guaranteed by us to the extent described below under “Trust Guarantees.”

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Specific United States federal income tax considerations applicable to an investment in trust preferred securities will be described in the applicable prospectus supplement.

In connection with the issuance of trust preferred securities, the Capital Trust will also issue one series of trust common securities. The restated declaration will authorize the administrative trustee(s) of the Capital Trust to issue on behalf of the Capital Trust one series of trust common securities having the terms, including dividends, conversion, redemption, voting, liquidation rights or the restrictions described in the restated declaration. Except as otherwise provided in the applicable prospectus supplement, the terms of the trust common securities issued by the Capital Trust will be substantially identical to the terms of the trust preferred securities issued by the Capital Trust, and the trust common securities will rank on equal terms with, and payments will be made on a ratable basis with, the trust preferred securities. However, upon an event of default under the restated declaration, the rights of the holders of the trust common securities to payment in respect of dividends and payments upon liquidation, redemption and otherwise will be subordinated to the rights of the trust preferred securities holders. Except in limited circumstances, the trust common securities will also carry the right to vote and appoint, remove or replace any of the trustees of the related trust. All of the trust common securities of the Capital Trust will be directly or indirectly owned by us.

The applicable prospectus supplement will describe whether we and/or certain of our subsidiaries maintain deposit accounts and conduct other banking transactions, including borrowings in the ordinary course of business, with the institutional trustee.

Trust Guarantees

Below is a summary of information concerning the trust guarantees that will be executed and delivered by us, at various times, for the benefit of the trust preferred securities holders. The applicable prospectus supplement will describe any significant differences between the actual terms of the trust guarantees and the summary below. This summary does not describe all exceptions and qualifications contained in the indenture or all of the terms of the trust guarantees. You should read the trust guarantees for provisions that may be important to you. A copy of the trust guarantees has been filed as an exhibit to the registration statement of which this prospectus is a part.

General . We will irrevocably and unconditionally agree, to the extent described in the trust guarantees, to pay in full, to the trust preferred securities holders of the Capital Trust, the trust guarantee payments (as defined below), except to the extent paid by the Capital Trust, as and when due, regardless of any defense, right of set-off or counterclaim which the Capital Trust may have or assert. Our obligation to make a trust guarantee payment may be satisfied by direct payment of the required amounts by us to the trust preferred securities holders or by causing the applicable Capital Trust to pay the required amounts to the holders.

The following payments regarding the trust preferred securities, which we refer to as the trust guarantee payments, to the extent not paid by the Capital Trust, will be subject to the trust guarantees, without duplication:

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Covenants of Argo Group. In each trust guarantee, we will covenant that, so long as any trust preferred securities issued by the Capital Trust remain outstanding, and if there will have occurred any event that would constitute an event of default under the trust guarantee or the restated declaration, we will not do any of the following:

However, even during such circumstances, we may:

Amendment and Assignment. Except regarding any changes that do not adversely affect the rights of trust preferred securities holders of the Capital Trust, in which case no vote will be required, the trust guarantees regarding the trust preferred securities may be changed only with the prior approval of the holders of not less than a majority in liquidation preference of the outstanding trust preferred securities. The manner of obtaining the approval of trust preferred securities holders will be as described in the applicable prospectus supplement. All guarantees and agreements contained in the trust guarantees will bind our successors, assigns, receivers, trustees and representatives and for the benefit of the holders of the outstanding trust preferred securities.

Termination of the Trust Guarantees . Each trust guarantee will end as to the trust preferred securities issued by the Capital Trust upon any of the following:

Each trust guarantee will continue to be effective or will be reinstated, as the case may be, if at any time any holder of trust preferred securities issued by the Capital Trust must restore payment of any sums paid under the trust preferred securities or the trust guarantee.

Each trust guarantee represents a guarantee of payment and not of collection. Each trust guarantee will be deposited with the institutional trustee to be held for the benefit of the trust preferred securities of the applicable

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Capital Trust. The institutional trustee will have the right to enforce the trust guarantees on behalf of the trust preferred securities holders of the Capital Trust. The holders of not less than a majority in aggregate liquidation preference of the trust preferred securities of the Capital Trust will have the right to direct the time, method and place of conducting any proceeding for any remedy available in respect of the applicable trust guarantee, including the giving of directions to the institutional trustee.

If the institutional trustee fails to enforce a trust guarantee as provided above, any holder of trust preferred securities of the applicable Capital Trust may institute a legal proceeding directly against us to enforce its rights under the trust guarantee, without first instituting a legal proceeding against the applicable Capital Trust, or any other person or entity. Each trust guarantee will not be discharged except by payment of the trust guarantee payments in full to the extent not paid by the Capital Trust, and by complete performance of all obligations under the trust guarantee.

Governing Law . Each trust guarantee will be governed by, and construed in accordance with, the laws of the State of New York.

The applicable prospectus supplement will set out the status of the trust guarantee.

Expenses of the Capital Trust

Subject to Bermuda law, we will agree to pay all of the costs, expenses or liabilities of the Capital Trust, other than obligations of the Capital Trust to pay to the holders of any trust preferred securities or trust common securities the amounts due pursuant to the terms of the trust preferred securities or trust common securities.

DESCRIPTION OF ARGO US DEBT SECURITIES AND DEBT GUARANTEES

The following description of the debt securities of Argo US sets forth certain general terms and provisions of such debt securities to which this prospectus and any prospectus supplement may relate, and such description does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all the provisions of the indentures, including the supplemental indentures or officers’ certificates to be filed in an amendment to the registration statement of which this prospectus is a part or filed in a Current Report on Form 8-K and incorporated by reference in the registration statement of which this prospectus is a part. The particular terms of any series of debt securities and the extent to which the general provisions may apply to a particular series of debt securities will be described in a prospectus supplement relating to that series. Argo US may issue senior debt securities or subordinated debt securities under indentures with a trustee to be chosen by Argo US and qualified to act under the Trust Indenture Act of 1939, as amended.

The material provisions of the indentures are summarized below. The summary is not complete. The senior debt securities of Argo US are to be issued under an indenture (the “Argo US senior indenture”), the form of which is filed as an exhibit to this registration statement of which this prospectus forms a part. The subordinated debt securities of Argo US are to be issued under an indenture (the “Argo US subordinated indenture”), the form of which is filed as an exhibit to this registration statement of which this prospectus forms a part. The senior indenture and the subordinated indenture are sometimes referred to herein, collectively, as the “Argo US indentures” and each, individually, as an “Argo US indenture.” You should read the Argo US indentures for provisions that may be important to you.

Because we have included only a summary of the material indenture terms, you must read the Argo US indentures (including any supplemental indenture or officers’ certificate filed with respect thereto) in full to understand every detail of the terms of the Argo US debt securities.

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General

Argo US may issue debt securities from time to time in one or more series without limitation as to aggregate principal amount. The senior debt securities will be unsecured and unsubordinated obligations and will rank equally and ratably with the other unsecured and unsubordinated obligations of Argo US. The subordinated debt securities will be unsecured obligations and will be subordinated in right of payment, as set forth in the subordinated indenture, to the prior payment in full of the existing and future senior indebtedness of Argo US.

Unless otherwise indicated in the prospectus supplement, principal of, premium, if any, and interest on the debt securities will be payable, and the transfer of debt securities will be registrable, at any office or agency maintained by Argo US for that purpose. Unless otherwise indicated in the applicable prospectus supplement, the debt securities will be issued only in denominations of $1,000 or integral multiples thereof. No service charge will be made for any registration of transfer or exchange of the debt securities, but Argo US may require you to pay a sum sufficient to cover any tax or other governmental charge imposed in connection with the transfer or exchange.

Argo US will prepare a prospectus supplement for each series of debt securities that it issues. Each prospectus supplement will set forth the applicable terms of the debt securities to which it relates. These terms will include some or all of the following:

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Argo US may offer and sell the debt securities as original issue discount securities at a substantial discount below their stated principal amount. The prospectus supplement will describe the U.S. federal income tax consequences and other special considerations applicable to original issue discount securities and any debt securities the federal tax laws treat as having been issued with original issue discount. “Original issue discount securities” means any debt security which provides for an amount less than its principal amount to be due and payable upon the declaration of acceleration of the maturity of the debt security upon the occurrence and continuation of an event of default.

The indenture does not contain covenants or other provisions designed to afford holders of the debt securities protection in the event of a highly leveraged transaction, change in credit rating or other similar occurrence.

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The above is not intended to be an exclusive list of the terms that may be applicable to any debt securities and Argo US is not limited in any respect in its ability to issue debt securities with terms different from or in addition to those described above or elsewhere in this prospectus, provided that the terms are not inconsistent with the indenture.

Guarantees

The payment obligations of Argo US pursuant to the debt securities will be fully and unconditionally guaranteed by Argo Holdings. None of the subsidiaries of Argo Holdings will guarantee or have an obligation in respect of the debt securities.

Global Debt Securities

Notes and the related guarantees may be issued in the form of one or more fully registered global securities which will be deposited with, or on behalf of, The Depository Trust Company, New York, New York (the “Depositary” or “DTC”) and registered in the name of Cede & Co., the Depositary’s nominee. Beneficial interests in the global securities may be represented through book-entry accounts of financial institutions acting on behalf of beneficial owners as direct and indirect participants in the Depositary.

Investors may elect to hold interests in the global securities through the Depositary, if they are participants in such systems, or indirectly through organizations which are participants in such systems. Except as described below, the global securities may be transferred, in whole and not in part, only to another nominee of the Depositary or to a successor of the Depositary or its nominee.

So long as the Depositary or its nominee is the registered owner of the global securities, the Depositary or its nominee, as the case may be, will be considered the sole owner or holder of the notes represented by the global securities for all purposes under the indenture. Except as provided below, owners of beneficial interests in the global securities will not be entitled to have notes represented by the global securities registered in their names, will not receive or be entitled to receive physical delivery of notes in definitive form, and will not be considered the owners or holders thereof under the indenture.

Principal and interest payments on notes registered in the name of the Depositary or its nominee will be made to the Depositary or its nominee, as the case may be, as the registered owner of the global securities. None of Argo US, the trustee, any paying agent, or registrar for the notes will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial interests in the global securities or for maintaining, supervising, or reviewing any records relating to those beneficial interests.

We expect that the Depositary or its nominee, upon receipt of any payment of principal or interest, will credit the participants’ accounts with payments in amounts proportionate to their respective beneficial interests in the principal amount of the global securities as shown on the records of the Depositary or its nominee. We also expect that payments by participants to owners of beneficial interests in the global securities held through these participants will be governed by standing instructions and customary practices, as is now the case with securities held for the accounts of customers in bearer form or registered in “street name.” The participants are responsible for the standing instructions and customary practices governing beneficial interests.

The Depositary and the direct and indirect participants will send notices and communications to direct and indirect participants and beneficial owners, as the case may be, in accordance with the arrangements governing their relationships, subject to any statutory or regulatory requirements as may be in effect from time to time.

DTC has provided us the following information: DTC is a limited-purpose trust company organized under the laws of the State of New York, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform

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Commercial Code and a “clearing agency” registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934. DTC holds and provides asset servicing for U.S. and non-U.S. equity, corporate and municipal debt issues and money market instruments that DTC’s participants, referred to as “direct DTC participants,” deposit with DTC. DTC also facilitates the post-trade settlement among direct participants of sales and other securities transactions in deposited securities through electronic computerized book-entry transfers and pledges between direct participants’ accounts, thereby eliminating the need for physical movement of certificates. Direct DTC participants include both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation, which is owned, in part, by a number of direct DTC participants. Indirect access to the DTC system is also available to others, referred to as “indirect DTC participants,” for example, securities brokers and dealers, banks, trust companies and clearing corporations, that clear through or maintain a custodial relationship with a direct DTC participant, either directly or indirectly. DTC rules applicable to direct and indirect participants are on file with the SEC.

Beneficial interests in a global security will be shown on, and transfers of beneficial interests in the global security will be made only through, records maintained by DTC and its participants, both direct and indirect. When you purchase debt securities through the DTC system, the purchases must be made by or through a direct DTC participant, which will receive credit for the debt securities in its account on DTC’s records. When you actually purchase the debt securities, you will become their beneficial owner. Your ownership interest will be recorded only on the direct or indirect DTC participants’ records. DTC will have no knowledge of your individual ownership of the debt securities. DTC’s records will show only the identity of the direct DTC participants and the amount of the debt securities held by or through them. You will not receive a written confirmation of your purchase or sale or any periodic account statement directly from DTC. You should instead receive these confirmations and account statements from the direct or indirect DTC participant through which you purchase the debt securities. The direct or indirect DTC participants are responsible for keeping accurate account of the holdings of their customers. The trustee will wire payments on the debt securities to the DTC nominee that is the registered holder of the debt securities. The trustee and we will treat DTC or its nominee as the owner of each global security for all purposes. Accordingly, the trustee, any paying agent, and we (including Argo US) will have no direct responsibility or liability to pay amounts due on a global security to you or any other beneficial owners in that global security. Any redemption notices will be sent by Argo US directly to DTC, which will, in turn, inform the direct or indirect DTC participants, which will then contact you as a beneficial holder.

Under the rules, regulations and procedures creating and affecting DTC and its operations, DTC is required to make book-entry transfers between direct DTC participants on whose behalf it acts with respect to the debt securities and is required to receive and transmit distributions of principal of and premium, if any, and interest on the debt securities. Direct and indirect DTC participants with which investors have accounts with respect to the debt securities similarly are required to make book-entry transfers and receive and transmit payments on behalf of their respective investors.

As DTC can only act on behalf of direct DTC participants, who in turn act on behalf of indirect DTC participants and certain banks, the ability of a person having a beneficial interest in a security held in DTC to transfer or pledge that interest to persons or entities that do not participate in the DTC system, or otherwise take actions in respect of that interest, may be affected by the lack of a physical certificate representing that interest. The laws of some states of the United States require that certain persons take physical delivery of securities in definitive form in order to transfer or perfect a security interest in those securities. Consequently, the ability to transfer beneficial interests in a security held in DTC to those persons may be limited.

DTC has advised us that it will take any action permitted to be taken by a holder of debt securities under the terms and conditions of the debt securities (including, without limitation, the presentation of debt securities for exchange) only at the direction of one or more of the direct DTC participants to whose accounts with DTC interests in the relevant debt securities are credited, and only in respect of the portion of the aggregate principal

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amount of the debt securities as to which that direct DTC participant or those direct DTC participants has or have given the direction. However, in certain circumstances described below, DTC will exchange the global securities held by it for certificated debt securities, which it will distribute to the direct DTC participants.

It is DTC’s current practice, upon receipt of any payment of distributions or liquidation amounts, to proportionately credit direct DTC participants’ accounts on the payment date based on their holdings of the relevant securities. In addition, it is DTC’s current practice to pass through any consenting or voting rights to such direct DTC participants by using an omnibus proxy. Consequently, those direct DTC participants should, in turn, make payments to and solicit votes from you, the ultimate owner of debt securities, based on their customary practices. Payments to you with respect to your beneficial interest in any debt securities will be the responsibility of the direct and indirect DTC participants and not of DTC, the trustee or us.

Individual certificates in respect of the notes will be issued in exchange for the global securities only if:

In the event that individual certificates are issued, holders of the notes will be able to receive payments (including principal and interest) on the notes and effect transfer of the notes at the offices of Argo US’s paying agent.

Title to book-entry interests in the notes will pass by book-entry registration of the transfer within the records of DTC in accordance with their respective procedures. Book-entry interests in the notes may be transferred within DTC in accordance with procedures established for this purpose by DTC.

The information in this section concerning DTC and DTC’s book-entry system has been obtained from sources that we believe to be reliable, but we take no responsibility for the accuracy thereof. Furthermore, DTC has no obligation to perform or continue to perform the procedures described above, and may discontinue or change those procedures at any time.

Events of Default

With respect to a series of debt securities, any one of the following events will constitute an event of default under the indenture:

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If any event of default occurs and continues, either the trustee or the holders of at least 25 percent in aggregate principal amount of the outstanding debt securities of that series may declare the principal amount of all the debt securities of that series or, if the debt securities of that series are original issue discount securities, the portion of the principal amount as may be specified in the terms of those debt securities, to be due and payable immediately by a notice in writing to Argo US and Argo Holdings, and to the trustee if given by holders. The principal amount (or specified amount) will then be immediately due and payable. If an event of default occurs involving the bankruptcy, insolvency or reorganization of Argo US or Argo Holdings, the principal amount of all outstanding securities under the indenture will be due and payable immediately without any action on the part of the trustee or the holders. After acceleration, but before a judgment or decree based on acceleration has been obtained, the holders of a majority in aggregate principal amount of outstanding debt securities of that series may, under certain circumstances, rescind and annul the acceleration.

The prospectus supplement relating to any series of debt securities that are original issue discount securities will contain the particular provisions relating to acceleration of the stated maturity of a portion of the principal amount of that series of original issue discount securities upon the occurrence and continuation of an event of default.

Each indenture provides that, subject to the duty of the trustee during default to act with the required standard of care, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request or direction of any of the holders, unless the holders offer the trustee indemnity. Generally, the holders of a majority in aggregate principal amount of the debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee.

A holder of any series of debt securities will not have any right to institute any proceeding with respect to the indenture, or for the appointment of a receiver or trustee, or for any other remedy, unless:

However, these limitations do not apply to a suit instituted by a holder for enforcement of payment of the principal of and premium, if any, or interest on their debt security on or after the respective due dates.

We are required to furnish to the trustee annually a statement as to our performance of certain obligations under the applicable indenture and as to any default.

Modification and Waiver

Argo US, Argo Holdings and the indenture trustee may, subject to obtaining any required consents with respect thereto, change or supplement an indenture without the consent of any holders with respect to certain matters, including:

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In addition, under the indentures, Argo US, Argo Holdings and the indenture trustee may add, change or eliminate any provisions of the indentures with the consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected, provided that the following actions require the consent of each holder affected:

The holders of not less than a majority in aggregate principal amount of the outstanding debt securities of any series may, on behalf of all holders of that series, waive any past default under the indenture, except a default in respect of a covenant or provision of the indenture that cannot be modified or amended without the consent of those holders of each outstanding debt security of that series who were affected.

Consolidation, Merger and Sale of Assets

Neither Argo US nor Argo Holdings may consolidate with or merge into or amalgamate with any other company or entity or sell, assign, transfer, lease or otherwise convey all or substantially all its assets to another company or entity, unless:

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Defeasance and Covenant Defeasance

The indenture provides, unless otherwise indicated in the prospectus supplement relating to that particular series of debt securities, that, at our option, Argo US and Argo Holdings:

in each case, if Argo US or Argo Holdings deposits, in trust, with the trustee money or U.S. government obligations, which through the payment of interest and principal in accordance with their terms will provide money, in an amount sufficient to pay all the principal of and premium, if any, and interest on the debt securities of that series on the dates such payments are due, which may include one or more redemption dates that we designate, in accordance with the terms of the debt securities of that series

We may establish this trust only if, among other things:

If Argo US or Argo Holdings fails to comply with its remaining obligations under the indenture after a defeasance of the indenture with respect to the debt securities of any series as described under the second item of the preceding sentence and the debt securities of such series are declared due and payable because of the occurrence of any event of default, the amount of money and U.S. government obligations on deposit with the trustee may be insufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. Argo US and Argo Holdings will, however, remain liable for those payments.

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Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the laws of the State of New York.

Certain Covenants of Argo US

Unless otherwise specified in the prospectus supplement, the following covenants will apply to the senior debt securities issued by Argo US.

Limitation on Liens. Argo Holdings shall not, and shall not permit its restricted subsidiaries to, issue, assume, incur or enter into a guarantee of, any indebtedness for borrowed money secured by a mortgage, pledge, lien, encumbrance or other security interest, directly or indirectly, upon any voting shares of a restricted subsidiary which are now owned or hereafter acquired by Argo Holdings or its subsidiaries without effectively providing concurrently that the senior debt securities (and if Argo US or Argo Holdings so elects, any other indebtedness of Argo US or Argo Holdings ranking on a parity with the senior debt securities) shall be secured equally and ratably with, or prior to, any such secured indebtedness so long as such indebtedness remains outstanding. This restriction shall not apply to permitted liens.

Restrictions on Certain Dispositions. As long as any of the senior debt securities remain outstanding, and except in a transaction otherwise expressly permitted by the Indenture, (1) issue, sell, assign, transfer or otherwise dispose of any capital stock of, or securities convertible into, or warrants, rights or options to subscribe for or purchase shares of capital stock of, any restricted subsidiary (other than to Argo US, Argo Holdings or another restricted subsidiary); or (2) permit any restricted subsidiary to issue (other than to Argo US, Argo Holdings or another restricted subsidiary) any capital stock (other than director’s qualifying shares) of, or securities convertible into, or warrants, rights or options to subscribe for or purchase any capital stock of, any restricted subsidiary; if, after giving effect to any transaction described in clauses (1) or (2) above and the issuance of the maximum number of shares or other equity interests issuable upon the conversion or exercise of all such convertible securities, warrants, rights or options, Argo Holdings would own, directly or indirectly, less than 80% of the capital stock of such restricted subsidiary; provided, however, that this covenant shall not prohibit (i) any issuance, sale, assignment, transfer or other disposition made for at least a fair market value consideration as determined by the board of directors of Argo Holdings pursuant to a resolution adopted in good faith; and (ii) any such issuance or disposition of securities if required by any law or any regulation or order of any applicable governmental or insurance regulatory authority. Notwithstanding the foregoing, Argo Holdings shall be permitted (A) to merge or consolidate any restricted subsidiary into or with another direct or indirect subsidiary of Argo Holdings, the capital stock of which Argo Holdings owns, directly or indirectly, at least 70%; and (B) subject to the provisions of the indenture relating to consolidation, merger, and/or sale of all or substantially all of the assets of Argo Holdings or Argo US and described above in “—Consolidation, Merger and Sale of Assets”, sell, assign, transfer or otherwise dispose of all of the capital stock of any restricted subsidiary at one time for at least a fair market value consideration as determined by the board of directors of Argo Holdings pursuant to a resolution adopted in good faith.

The following are the meanings of terms that are important in understanding the restrictive covenants described above:

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Subordination of Subordinated Debt Securities

The subordinated debt securities of each series will, to the extent set forth in the subordinated indenture, be subordinate in right of payment to the prior payment in full of all senior indebtedness with respect to such series. Upon any payment or distribution of assets of any kind or character, whether in cash, property or securities, to creditors upon any dissolution, winding-up, liquidation or reorganization, whether voluntary or involuntary, or in bankruptcy, insolvency, receivership or other proceedings, all amounts due upon all senior indebtedness with respect to the subordinated debt securities of any series will first be paid in full, or payment thereof provided for in money in accordance with its terms, before the holders of subordinated debt securities of such series are entitled to receive or retain any payment on account of principal of, or any premium or interest on, or any additional amounts with respect to, the subordinated debt securities of such series, and to that end the holders of such senior indebtedness shall be entitled to receive, for application to the payment thereof, any payment or distribution of any kind or character, whether in cash, property or securities, including any such payment or distribution which may be payable or deliverable by reason of the payment of any other indebtedness being subordinated to the payment of subordinated debt securities of such series, which may be payable or deliverable in respect of the subordinated debt securities of such series upon any such dissolution, winding-up, liquidation or reorganization or in any such bankruptcy, insolvency, receivership or other proceeding.

By reason of such subordination, in the event of liquidation or insolvency, holders of senior indebtedness with respect to the subordinated debt securities of any series and holders of other obligations that are not subordinated to such senior indebtedness may recover more ratably than the holders of the subordinated debt securities of such series.

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Subject to the payment in full of all senior indebtedness with respect to the subordinated debt securities of any series, the rights of the holders of the subordinated debt securities of such series will be subrogated to the rights of the holders of such senior indebtedness to receive payments or distributions of cash, property or securities applicable to such senior indebtedness until the principal of, any premium and interest on, and any additional amounts with respect to, the senior indebtedness with respect to the subordinated debt securities of such series have been paid in full.

No payment of principal (including redemption and sinking fund payments) of or any premium or interest on or any additional amounts with respect to the subordinated debt securities of any series may be made (1) if any senior indebtedness with respect to such series is not paid when due and any applicable grace period with respect to such default has ended and such default has not been cured or waived or ceased to exist, or (2) if the maturity of any senior indebtedness with respect to such series has been accelerated because of a default.

The subordinated indenture does not limit or prohibit Argo US from incurring additional senior indebtedness, which may include indebtedness that is senior to the subordinated debt securities of any series, but subordinate to its other obligations. The senior debt securities will constitute senior indebtedness with respect to the subordinated debt securities of each series under the subordinated indenture.

Under the subordinated indenture, “senior indebtedness” includes all of Argo US’s obligations to pay principal, premium and interest:

The following types of indebtedness will not rank senior to the subordinated debt securities:

The subordinated indenture provides that the foregoing subordination provisions, insofar as they relate to any particular series of subordinated debt securities, may be changed prior to such issuance. Any such change would be described in the related prospectus supplement.