Exhibit 4.52**TRANSACTION AGREEMENT**          This Transaction Agreement dated as of May 9, 2007 (the “**Agreement**”) is entered into by andbetween SCOR S.A., a *société anonyme*organized and existing under the laws of the French Republic(“**SCOR**” or the “**Offeror**”), and Converium Holding AG, an *Aktiengesellschaft*organized and existingunder the laws of Switzerland (“**Converium**” or the “**Company**” and, together with the Offeror, the“**Parties**”). Capitalized terms not expressly defined herein shall have the meaning ascribed to themin the Offer Prospectus (as defined below).     WHEREAS, on April 5, 2007, the Offeror has published a public tender offer in Switzerland forall the publicly held registered shares with a nominal value of CHF 5 each of Converium publishedon April 5, 2007 (the “**Offer**”, the prospectus relating to the Offer being referred to as the “**OfferProspectus**”);     WHEREAS, the Parties firmly believe that relations based on trust, mutual understanding andrespect are an essential element in the reinsurance industry;     WHEREAS, the Offeror has agreed to modify the Offer pursuant to the terms set forth herein(the “**Modified Offer**”) and to take certain other actions as set forth below;     WHEREAS, the board of Directors of the Company (the “**Company Board**”) has agreed to recommendand support acceptance of the Modified Offer and to take certain other actions as set forth below;     NOW, THEREFORE, in consideration of the mutual representations, warranties, covenants andagreements set forth herein, intending to be legally bound hereby, the Parties hereby agree asfollows:ARTICLE IMODIFIED OFFER     Section 1.1 Offer Price. Subject to the terms and conditions set forth herein and inthe Offer Prospectus, SCOR hereby agrees (i) to increase the Offer Price, for each Converium Sharetendered, to (a) 0.5 New SCOR Shares with a nominal value of EUR 7.8769723 each and (b) CHF 5.50 incash and (ii) not to reduce the Offer Price by the proposed gross dividend of CHF 0.20 perConverium Share. The other provisions of Section B.3 of the Offer Prospectus shall remainunchanged.     Section 1.2 Other Terms and Conditions of Modified Offer. The other terms andconditions of the Offer, as set forth in the Offer Prospectus, shall remain unchanged.     Section 1.3 Announcement of the Modified Offer. The Parties’ agreement on theModified Offer will be announced on May 10, 2007 at 7:00 a.m. CET by way of mutually agreed pressreleases which shall *inter alia*make explicit reference to the Company Board’s unanimous approvaland recommendation as well as the support of the Company’s Global Executive Committee of suchModified Offer.     Section 1.4 Modified Offer Prospectus. Subject to Sections 2.1 and 5.2 below, theOfferor shall publish a modified Prospectus reflecting the Modified Offer (the “**ModifiedProspectus**”) no later than two (2) SWX trading days following the approval of the Modified Offer bythe Swiss Takeover Board. 1 Final version transaction agreement SCOR/Converium
 

 
ARTICLE IIRECOMMENDATION OF THE MODIFIED OFFER     Section 2.1 Recommendation. The Company Board has unanimously resolved at itsmeeting held on May **[9]**, 2007, subject to a Superior Offer (as defined below) not having been madeor formally pre-announced in the meantime (subject to Section 4.2 below), (i) to recommend to theCompany’s shareholders to accept the Modified Offer and tender their Converium Shares into theModified Offer and (ii) to unanimously adopt and publish, as part of the Modified Prospectus, amodified Company Board report prepared in accordance with Art. 29 para. 1 of the Swiss Federal Acton Stock Exchanges and Securities Trading (“**SESTA**”) endorsing and recommending the Modified Offerwithout reservation and recommending that the Company’s shareholders accept such Modified Offer(the “**Modified Company Report**”). In this context, the Company will ensure that the ModifiedCompany Report be prepared as soon as reasonably practicable after the date hereof and that theModified Company Report will be filed with the Swiss Takeover Board for approval jointly with theModified Prospectus.     Section 2.2 Actions of Company Board. As from the date hereof, (i) the Company Boardand the members of the Global Executive Committee shall, subject to a Superior Offer not havingbeen announced or pre-announced (subject to Section 4.2 below), publicly support the ModifiedOffer and (ii) the Company shall abstain from taking any action or doing, or cause to abstain fromdoing, any such thing that may (a) prevent or compromise the Modified Offer, its success or itsstrategic or commercial value or rationale or (b) be otherwise detrimental to the Modified Offer.ARTICLE IIIOFFEROR COVENANTS     Section 3.1 Swiss Presence. Subject to the settlement of the Modified Offer, theOfferor agrees to (i) maintain a strong presence in Zurich and (ii) make Zurich one of the threeEuropean key hubs of the combined Group, together with Paris and Cologne. The Zurich operatingentity shall become a strategic pillar of the combined Group.     Section 3.2 Swiss Employees. Subject to the settlement of the Modified Offer, for aperiod of twelve (12) months following the date of settlement of the Modified Offer, the Offeroragrees to ensure that the Company and its Swiss subsidiaries do not serve notice to any of theirpresent employees or change the compensation plans for such employees. During such period, theCompany and its Swiss subsidiaries may, however, terminate employees for *cause (wichtigem Grund ,Art.337CO)*. The foregoing limitations to serve notice shall not be applicable to any presentemployees of the Company and its Swiss subsidiaries who have a Change in Control clause in theiremployment agreements and such employment agreements will continue to apply.     Section 3.3 Specific Key Employees. Subject to the settlement of the Modified Offer,the employment agreements of Ms. Inga Beale and Mr. Paolo De Martin shall be terminated with effectas of December 31, 2007 by the termination agreements attached hereto as Exhibits 1a and 1brespectively. The Company Board hereby confirms that it has obtained the approval of Ms. IngaBeale and Mr. Paolo De Martin who have agreed to use, until December 31, 2007, their best efforts to ensure a smooth transition of the management of theCompany to the Offeror and to act in a loyal manner. 2 Final version transaction agreement SCOR/Converium
 

 
     Section 3.4 SWX Secondary Listing. Upon settlement of the Modified Offer or assoon as reasonably practicable thereafter, a secondary listing of the Offeror’s shares on the SWXExchange shall be implemented.     Section 3.5 Protection of the Members of the Company Board. Subject to the settlementof the Modified Offer, the Offeror agrees, subject to applicable laws and regulations, to releaseand discharge, to the extent permitted in accordance with applicable laws and regulations, each ofthe members of the Company Board from any and all claims and liabilities which the Company has ormay have against any member arising out of any matter, cause or event occurring on or before thedate of the EGM (as defined below), provided that the foregoing shall not apply in connection withany willful or grossly negligent acts or omissions of a member. Furthermore, the Offeror shallensure that the Company maintains for six (6) years as of the date hereof tail insurance for thepresent members of the Company Board and officers of the Company and its subsidiaries that is basedon the present D&O insurance of the Company and provides the same coverage as such insurance.ARTICLE IVCOMPANY COVENANTS     Section 4.1 Conduct of Business. To the extent permitted under applicable laws andregulations, the Company shall, for the whole duration of this Agreement, (i) operate (and shallprocure that its affiliates operate) its business and the businesses of its affiliates in theordinary course of business consistent with past practice, (ii) abstain (and shall procure that itsaffiliates and representatives abstain) from (a) taking any actions outside the ordinary course ofbusiness consistent with past practice and (b) issuing any type of equity securities or debtinstrument of any nature whatsoever, and (iii) shall, and shall cause each of its affiliates to,use all reasonable commercial efforts to preserve intact its material business organization andrelationships with third parties (including its relationships with ceding companies, suppliers,employees, financial institutions and business partners) and to keep available the services oftheir present officers and key employees. The Company shall in particular ensure that it or itsaffiliates do not undertake any action that triggers the Offer Conditions (as defined in Section5.2 below).     Section 4.2 No Solicitation. The Company shall immediately cease and cause to beterminated all existing discussions or negotiations with any party conducted heretofore withrespect to any Acquisition Proposal (as defined below) and not initiate or solicit in any way anydiscussions or negotiations with respect to any Acquisition Proposal after the date hereof. TheCompany shall promptly notify the Offeror (i) if it becomes aware that a third party has theintention of announcing or pre-announcing an Acquisition Proposal and (ii) of any AcquisitionProposal received after the date hereof, in each case, not later than twenty four (24) hours afterthe knowledge or the receipt of such Acquisition Proposal. Except on a date that is not earlierthan the fourth (4th) business day following a Notice of a Superior Offer (as defined below), theCompany Board shall not (i) withdraw or modify in a manner adverse to the Offeror, or proposepublicly to withdraw or modify in a manner adverse to the Offeror, the approval or recommendationby the Company Board set forth in the Modified Company Report, or (ii) approve or recommend, orpropose publicly to approve or recommend, any Superior Offer. The Company shall promptly (and inany event within one (1) business day) notify the Offeror following any determination by theCompany Board with respect to an Acquisition Proposal, that such Acquisition Proposal is a SuperiorOffer (“**Notice of Superior Offer**”). During the three (3) business day period after receipt of theNotice of Superior Offer, the Offeror shall have reasonable opportunity to propose suchadjustments, modifications or amendments to the terms and conditions of this Agreement as the Offeror believes would enable the Company Board toproceed with the transactions contemplated herein (*provided, however,*that the Offeror shall 3 Final version transaction agreement SCOR/Converium
 

 
not have any obligation to propose any adjustment, modification or amendment to the terms andconditions of this Agreement or the Modified Offer) and the Company shall negotiate with theOfferor in good faith with respect thereto during such three (3) business day period.     For purposes hereof, (1) “**Acquisition Proposal**” shall mean any proposal or offer from anyparty other than the Offeror relating to any (i) tender or exchange offer involving ConveriumShares or other acquisition of Converium Shares, (ii) merger, consolidation or other businesscombination involving the Company or any of its affiliates, (iii) direct or indirect acquisition orpurchase of a business or assets that constitutes a substantial part of the business or assets ofthe Company or its affiliates, or a substantial amount of the equity securities of the Company orany of its affiliates, (iv) recapitalization or restructuring of the Company, or (v) othertransaction similar to any of the foregoing with respect to the Company or any of its affiliates,other than the transactions contemplated by this Agreement and (2) “**Superior Offer**” shall mean anypublic offer (or an increase of an existing public offer) to all of the shareholders of the Companyto acquire all of the Converium Shares, on terms and conditions that the Company Board determinesin its good faith judgment, after due consideration of its fiduciary duties and based upon anopinion of independent financial and legal experts, to be superior for the Company’s shareholderswhen compared as a whole with the terms and conditions of the Modified Offer, provided such offeris at a price or consideration that on a fully diluted basis is not lower than the OfferConsideration and that the conditions to such offer are no more restrictive than the OfferConditions.     Section 4.3 Shareholders’ Meetings. In the annual shareholders’ meeting of theCompany that has been convened for May 10 2007 (“**AGM**”), the Company and the Company Board shall (i)(a) withdraw the proposal for a capital reduction for the purpose of a par value repayment toshareholders of the Company (agenda item 3) and (b) propose against any third party proposal for(x) such a capital reduction (or similar thereto) or (y) an increase of the proposed gross dividendof CHF 0.20 per Converium Share (agenda item 2), (ii) provide the Offeror’s Chairman and CEO theopportunity to address the Company’s shareholders and to explain the advantages of the combinationbetween Converium and SCOR and (iii) support the Modified Offer and the creation of the combinedGroup. In addition, the Company shall procure that Mr. Derrell J. Hendrix shall not stand forre-election as currently proposed under agenda item 5 of the AGM and the Company and the CompanyBoard shall instead announce Mr. Hendrix’ decision not to stand for re-election and propose to theAGM to support a proposal by the Offeror to elect in lieu of Mr. Hendrix Mr. Gilles Meyer, Directorof Business Unit 1 of SCOR Global Life and member of the SCOR Group Executive Committee, to theCompany Board for a term of three (3) years. If the Offer is declared successful, the CompanyBoard shall immediately convene an extraordinary meeting of shareholders of the Company to be heldas soon as practicable with such agenda and proposals that shall have been submitted by the Offeror(“**EGM**”).     Section 4.4 Trading in Shares and Related Securities by the Company. From the datehereof until the day of the six (6)-month anniversary of the additional acceptance period of theModified Offer (or any later period during which the Swiss best price rule may apply), the Companyshall abstain (and shall procure that its affiliates abstain) from (i) (a) acquiring or selling anyConverium Shares or (b) entering into any (x) agreement (either on or off exchange) relating to theacquisition or sale of Converium Shares and/or (y) derivative transaction having Converium Sharesas underlying; (ii) amending the terms and/or conditions of existing employee stock options orderivatives issued by the Company, its affiliates or representatives without the Offeror’s priorwritten consent; (iii) tendering treasury shares held or acquired by the Company or its affiliates(the “**Treasury Shares**”) for acceptance in the Modified Offer; and (iv) selling or agreeing to sellany of the Treasury Shares to any third party (other than the delivery of Treasury Shares tofulfill the share delivery obligations of the Company under the various employee participation plans in effect as of the date hereof).The Offeror is hereby informed that all rights of the beneficiaries under the Company’scurrently 4 Final version transaction agreement SCOR/Converium
 

 
existing stock options plan and stock purchase plan vest and become exercisable on the firstday of the extension period (art 14.para.5) of the Modified Offer. Due to the immediately precedingrestrictions, the Company may not have a sufficient number of shares to cover all its obligationsto deliver shares but will have to cover a proportion of the commitments under such stock optionsplan and stock purchase plan by paying full cash compensation for the value of the shares to bedelivered to the beneficiaries of such plans, unless an exemption from the provisions of thisSection 4.4 is granted by the Offeror to the Company.     Section 4.5 Rating Evaluation Service. The Company agrees to execute any and allrequired documents upon execution of this Agreement to permit a Rating Evaluation Service to beperformed by Standard & Poors’ as soon as practicable.     Section 4.6 US Litigation. Immediately following the execution of this Agreement, theCompany shall take all steps necessary to obtain dismissal with prejudice of the litigation itcommenced in the United States District Court for the Southern District of New York entitledConverium Holding AG v SCOR S.A. and Patinex AG, No. 07 CV 3042 (GEL). The Company shall also, inconnection with the putative class action commenced in the United States District Court for theSouthern District of New York entitled Sclater-Booth v SCOR S.A. and Patinex AG, No. 07 CV 3476,cooperate with the Offeror in the Offeror’s defense of that lawsuit, including by providingdocuments and testimony should the Offeror reasonably deem documents from the Company necessary toits defense of that lawsuit.     Section 4.7 Other Actions. Immediately following the execution of this Agreement, theCompany shall take all steps necessary to withdraw all its filings and claims for relief (*Anträge,Rechtsbegehren)*made to the Swiss Takeover Board and other Swiss governmental authorities(including the FOPI) and file its approval with the Offer and the Modified Offer with the SwissTakeover Board and other competent Swiss governmental authorities. The Company shall not oppose anyfilings of the Offeror with any governmental authority that aim at demonstrating that the Offeror’sexclusion of the United States has been carried out in compliance with applicable laws andregulations and cooperate with the Offeror in that regard.     Section 4.8 Seamless Transfer of Managerial Control. The Company and the members ofthe Company Board shall use their best effort to ensure a seamless and smooth transfer of themanagerial control over the Company to the Offeror immediately after the EGM of the Companymentioned in Section 4.3 above has been held. To ensure its control over the Company the Offerorwill at such EGM propose and elect new board members of the Company and will, furthermore, replacethe current CEO and the current CFO of the Company. Furthermore, the Company and its key employeesshall use their best efforts to maintain the relationships with the Company’s current clients andother stakeholders.     Section 4.9 Company Board. Provided that the Modified Offer is successful and becomesunconditional, all present members of the Company Board will resign with effect as of the EGM. TheOfferor will ensure that at such EGM new members of the Company Board are elected.ARTICLE VMUTUAL COVENANTS     Section 5.1 Announcement. The timing and content of any announcement, press release,or other public statement concerning this Agreement or any further agreement entered into betweenthe Offeror and the Company shall only occur upon, and be determined in advance by, mutualagreement and consent of each of the Parties, unless required by applicable 5 Final version transaction agreement SCOR/Converium
 

 
laws and regulations (in which case, the disclosing Party shall consult in advance with theother Party concerning the reasons for, and content of, such disclosure). Notwithstanding theforegoing, the Offeror shall be free to make filings to the Swiss Takeover Board and otherauthorities in support of the Modified Offer and its approval as deemed appropriate by the Offeror.          Section 5.2 Cooperation. From the date hereof and for the whole duration of thisAgreement, to the extent permitted under applicable laws and regulations, each of SCOR andConverium shall, and Converium shall cause each of its affiliates to, coordinate, cooperate and usecommercially reasonable best efforts: (i) to immediately contact and jointly meet with each of theSwiss Takeover Board and the Swiss Federal Office of Private Insurance (“**FOPI**”) to explain theconsequences of this Agreement from the Parties’ perspective; (ii) to duly publish the ModifiedProspectus, including the Modified Company Report, as set forth above; (iii) to take all actionsnecessary or advisable to consummate and make effective the transactions contemplated by thisAgreement as promptly as practicable, including (1) the approval of the FOPI for exceeding each ofthe 33% and the 50% thresholds of Converium’s share capital, (2) the fulfillment of the Offerconditions set forth in Section B.9 of the Offer Prospectus (the “**Offer Conditions**”), (3) the duesettlement of the Modified Offer in accordance with its terms, and (4) to obtain all consents,approvals, permits and authorizations required to be obtained from counterparties to agreementswhich are material to the business of the Company or its affiliates, including the agreementsentered into with Zurich Financial Services Group, National Indemnity, GAUM and MDU.          Section 5.3 Integration Committee. Upon execution of this Agreement, the Offeror andthe Company shall set up a joint committee the purpose of which will be to organize and anticipateon all matters that will be necessary in order to ensure a smooth integration process (the“**Integration Committee**”). The list of the members of such Integration Committee and its specificfunctions and governance will be agreed upon by the Parties, being understood that each Party shallhave an identical representation on such Integration Committee.          Section 5.4 Underwriting Committee. Upon execution of this Agreement, the Offeror andthe Company shall set up a joint committee the purpose of which will be to organize (i) thecombination of the Offeror’s “Dynamic Lift Plan” and the Company’s “Roadmap” and (ii) the 2008underwriting plan (the “**Underwriting Committee**”). The list of the members of such UnderwritingCommittee will be agreed upon by the Parties, being understood that each Party shall have anidentical representation on such Underwriting Committee.ARTICLE VIREPRESENTATIONS AND WARRANTIES     Each of the Parties hereby represents and warrants to the other Party as follows:     (a) Such Party has full corporate power and authority to execute and deliver this Agreement.The execution, delivery and performance by such Party of this Agreement have been duly authorizedby such Party’s Board of Directors, and no other corporate action on the part of such Party isnecessary to authorize the execution and delivery by such Party of this Agreement.     (b) This Agreement has been duly executed and delivered by such Party and, assuming due andvalid authorization, execution and delivery thereof by the other Party, this Agreement is a validand binding obligation of such Party enforceable against such Party in accordance with its terms, except as limited by applicable bankruptcy, insolvency and othersimilar applicable laws and regulations affecting enforcement of creditors’ rights generally. 6 Final version transaction agreement SCOR/Converium
 

 
     (c) Except as regards the U.S. litigation matters referred to in Section 4.6 above, thereis no suit, action, proceeding or arbitration pending against or, to the knowledge of such Party,threatened against or affecting such Party or its affiliates by any third party nor is there anyorder outstanding against such Party or any of its affiliates that (i) seeks to restrain or enjointhe consummation of any of the transactions contemplated by this Agreement, or (ii) couldreasonably be expected to negatively impair the ability of such Party to consummate any of thetransactions contemplated by this Agreement.ARTICLE VIITERMINATION     Section 7.1 Termination. This Agreement may be terminated: (i) by mutual writtenconsent of the Parties; or (ii) by any Party, if the Modified Offer is unsuccessful or is otherwisewithdrawn, upon public announcement by the Offeror of the Modified Offer’s lack of success orwithdrawal; or (iii) by the Offeror, if the Company materially breaches its representations,warranties or covenants under this Agreement; or (iv) by the Offeror, if the Company Boardwithdraws or fails to make its recommendation of the Offer, solely in a manner expressly permittedunder this Agreement; or (v) by the Company, if the Company Board withdraws or fails to make itsrecommendation of the modified Offer, solely in a manner expressly permitted under this Agreement;or (vi) by any Party, if a competing public tender offer has an acceptance rate of 50% or more ofall voting rights and is declared successful (subject to conditions subsequent by the relevantofferor).     Section 7.2 Liability. If the obligations under this Agreement are terminatedaccording to Section 7.1 above, such termination shall be without liability of any Party to theother Party; *provided*, *however*, that if such termination shall result from the breach by any Partyof its representations, warranties or covenants under this Agreement, such Party shall be fullyliable for all damages suffered by the other Party as a result of such breach.ARTICLE VIIIMISCELLANEOUS     Section 8.1 Fees and Expenses. All fees and expenses incurred in connection with thisAgreement and the consummation of the transactions contemplated herein shall be borne by the Partyincurring such fees or expenses.     Section 8.2 Consents to References. The Offeror and the Company shall be entitled toinclude in filings under applicable rules and regulations, including the SESTA, the GeneralRegulation of the *Autorite des marches financiers*, the U.S. Securities Act of 1933, as amended andthe U.S. Securities Exchange Act of 1934, as amended, information in connection with this Agreementand the transactions contemplated herein.     Section 8.3 Entire Agreement; No Third Party Beneficiaries. This Agreement and theExhibits hereto constitute the entire agreement and supersede all prior agreements andunderstandings, both written and oral, between the Parties with respect to the subject matterhereof and thereof. With the exception of Sections 3.3 and 3.5 hereof which confer rights to thethird parties expressly referred to in such Sections, this Agreement is not 7 Final version transaction agreement SCOR/Converium
 

 
intended to, and does not, confer upon any person other than the Parties hereto any rights orremedies hereunder.          Section 8.4 Amendments and Waivers. This Agreement may be amended, superseded,cancelled, renewed or extended, only by a written instrument signed by each of the Offeror and theCompany or, in the case of a waiver, only by a written instrument signed by the Party waivingcompliance. No delay on the part of any Party in exercising any right, power or privilegehereunder shall operate as a waiver thereof, nor shall any waiver on the part of any Party of anysuch right, power or privilege, nor any single or partial exercise of any such right, power orprivilege, preclude any further exercise thereof or the exercise of any other such right, power orprivilege.          Section 8.5 Binding Effect; Assignment. This Agreement shall be binding upon andinure to the sole benefit of the Parties hereto and their respective successors, heirs, permittedassigns and legal representatives and it shall not be construed as conferring any rights orremedies on any Person other than the Parties and their respective successors and permittedassigns. Pending settlement of the Modified Offer, neither this Agreement nor any of the rights,interests or obligations hereunder shall be assigned by either Party (whether by operation of lawor otherwise) without the prior written consent of the other Party. Following settlement of theModified Offer, the Offeror shall have the right to assign any or all of its rights and obligationsto any Affiliate of the Offeror. Any attempted assignment not permitted under this Section 8.5shall be null and void.          Section 8.6 Notices. All notices and other communications hereunder shall be inwriting and shall be deemed to have been given (i) on the date of delivery if delivered personallyor by courier service, (ii) on the date of confirmation of receipt (or the first business dayfollowing such receipt if the date is not a business day) if sent via facsimile (receiptconfirmed), or (iii) on the date of confirmation of receipt (or the first business day followingsuch receipt if the date is not a business day) if delivered by an internationally recognizedcourier service. All notices hereunder shall be delivered to the Parties at the followingaddresses or facsimile numbers:(i) If to the Offeror, to:SCOR S.A.