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                                    Form 6-K

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                        Report of Foreign Private Issuer

                        Pursuant to Rule 13a-16 or 15d-16
                     of the Securities Exchange Act of 1934

                         For the month of February, 2005

                              CONVERIUM HOLDING AG 
                 -----------------------------------------------
                 (Translation of registrant's name into English)

                                 Baarerstrasse 8
                                   CH-6300 Zug
                                  Switzerland 
                    ----------------------------------------
                    (Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports
under cover Form 20-F or Form 40-F.

                         Form 20-F __X__ Form 40-F ____

Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

                                Yes____ No __X__

If "Yes" is marked, indicate the file number assigned to the registrant in
connection with Rule 12g3-2(b): 82- Not Applicable






                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

                                        CONVERIUM HOLDING AG                  
                                                                              
                                                                              
                                                                              
                                                                              
                                        By: /s/ Dirk Lohmann                  
                                        ---------------------------------     
                                        Name: Dirk Lohmann                    
                                        Title: CEO                            
                                                                              
                                                                              
                                                                              
                                                                              
                                        By: /s/ Christian Felderer            
                                        ---------------------------------     
                                        Name: Christian Felderer              
                                        Title: General Legal Counsel          
                                        



Date: February 17, 2005







                           Converium Holding Ltd, Zug

Zug, Switzerland - February 17, 2005 - Converium today informs on the January 1,
2005 treaty renewals

Following its January renewals, Converium expects total gross premiums written
for 2005 to exceed US$ 2 billion, which is in line with expectations. 63% of the
Company's renewable non-life business volume (excluding Converium Reinsurance
(North America) Inc., which is in orderly run-off) was successfully maintained.
In Europe, Asia and Latin America Converium was able to retain 70% of directly
written non-life premiums and 55% of brokered non-life premiums up for renewal.
The Company succeeded in maintaining 87% of its treaty direct client
relationships and 56% of its treaty broker relationships. Converium also managed
to establish a significant number of new direct client and broker relationships.
Overall, the positive outcome of the January 2005 renewals testifies to the
resilience and viability of the Converium franchise.

Total gross premiums written for 2005 expected to exceed US$ 2 billion
Following the January renewals, Converium reports total in-force expected
premium income (non-life and life) of US$ 2.35 billion, which is inclusive of
US$ 839 million in non-life and life business up for renewal later this year.
Given the nature of the business still renewable, the Company expects total
gross premiums written in calendar year 2005 to exceed US$ 2 billion and total
gross premiums written in underwriting year 2005 of approximately US$ 2 billion.

Non-life renewals in line with expectations
In January, Converium renewed non-life contracts of US$ 1,243 million, i.e. 63%
of the business which was up for renewal (excluding Converium Reinsurance (North
America) Inc., which is in orderly run-off). As expected, Converium's current
financial strength ratings triggered substantial cancellations and share
reductions. At the same time, the Company's continued focus on underwriting
profitability caused it to decline about 5% of renewable business. This decrease
of renewed volume was partially offset by premium growth of US$ 282 million due
to rate or share increases as well as new or restructured business. Non-life
business worth US$ 714 million will be up for renewal later in 2005 (or US$ 605
million, excluding Converium Reinsurance (North America) Inc.).

Above-average business retention ratios in property and short-tail specialty
lines of business Converium's Standard Property & Casualty Reinsurance segment
renewed US$ 673 million of business, which represents a business retention ratio
of 63%. The Company's Specialty Lines segment recorded an identical retention
ratio of 63% and a corresponding renewal volume of US$ 570 million.



In the property, aviation and marine lines of business, Converium was successful
in preserving its franchise by retaining 68%, 72% and 74%, respectively, of
renewable business. This pattern reflects strong relationships with both clients
and intermediaries as well as access to business at its source, e.g. through
Global Aerospace Underwriting Managers Ltd.

Almost stable market position in parts of Europe as well as in Latin America
In its future core markets of Europe, Latin America and Asia Converium was able
to retain 60%, 94% and 71%, respectively, of its non-life business up for
renewal in January. As announced earlier, Converium has also continued to write
selective US property & casualty business from Zurich.

More specifically, Converium's franchise has proven particularly strong and
resilient in Germany, the world's third largest property & casualty market, with
a business retention ratio of 95%. In the Middle East region Converium even
managed to consolidate its position with a net growth of 3% of bound renewals.
In general, this outcome is evidence of the importance of long-standing client
and broker relationships.

Life & Health franchise maintained

Converium's life & health business is underwritten continuously throughout the
year. For 2005, the Company's Life & Health Reinsurance segment expects gross
premiums written of approximately US$ 325 million (excluding Converium
Reinsurance (North America) Inc.), which is roughly stable compared with 2004.
In Europe, Converium even recorded a noticeable increase of expected business.
Overall, the segment's positive outlook is reflective of well-established client
relationships and local distribution and servicing capabilities.

Majority of client relationships remain intact
During the January renewals Converium performed well in markets where the
Company had established long-lasting direct client relationships, access to top
decision-makers and a local market presence. Excluding its North American
subsidiary, Converium renewed US$ 868 million of non-life premiums written
directly with clients, i.e. 70% of the renewable total. 87% of all treaty direct
non-life client relationships were maintained, with lower, unchanged or even
higher business volumes. As expected, renewals were considerably more
challenging in broker markets where Converium's current financial strength
ratings led to a substantial loss of business. Nonetheless, Converium managed to
renew US$ 362 million, i.e. 55% of treaty brokered non-life premiums up for
renewal in January (excluding Converium Reinsurance (North America) Inc.). 56%
of the Company's treaty broker non-life relationships are intact. This is
expected to help Converium regain ground in brokered markets as soon as its
financial strength ratings have improved. The Company is also pleased to report
that it managed to establish a significant number of new direct and broker
relationships.

Adhering to profitability standards in softening markets
The January renewals were characterized by heightened competition and plentiful
capacity, which put pressure on rates, terms and conditions in certain markets.
Overall market conditions, however, remained attractive. Converium's
profitability-focused underwriting approach led it to decline business amounting
to approximately 5% of the premium volume renewable in January 2005. Converium's
adherence to the imperative of technical underwriting contributed to substantial
top-line reductions, for example in the motor line of business.


                                   * * * * * *

Enquiries:

Michael Schiendorfer                       Zuzana Drozd
Media Relations Manager                    Head of Investor Relations

michael.schiendorfer@converium.com         zuzana.drozd@converium.com

Phone:         +41 (0) 1 639 96 57         Phone:         +41 (0) 1 639 91 20
Fax:           +41 (0) 1 639 76 57         Fax:           +41 (0) 1 639 71 20


About Converium

Converium is an independent international multi-line reinsurer known for its
innovation, professionalism and service. Today Converium employs more than 700
people in 20 offices around the globe and is organized into three business
segments: Standard Property & Casualty Reinsurance, Specialty Lines and Life &
Health Reinsurance. Converium has a "BBB+" rating (outlook stable) from Standard
& Poor's and a "B++" rating (outlook stable) from A.M. Best Company.


Important Disclaimer

This document contains forward-looking statements as defined in the U.S. Private
Securities Litigation Reform Act of 1995. It contains forward-looking statements
and information relating to the Company's financial condition, results of
operations, business, strategy and plans, based on currently available
information. These statements are often, but not always, made through the use of
words or phrases such as 'expects', 'should continue', 'believes',
'anticipates', 'estimates' and 'intends'. The specific forward-looking
statements cover, among other matters, the reinsurance market, the outcome of
insurance regulatory reviews, the Company's operating results, the rating
environment and the prospect for improving results. Such statements are
inherently subject to certain risks and uncertainties. Actual future results and
trends could differ materially from those set forth in such statements due to
various factors. Such factors include general economic conditions, including in
particular economic conditions; the frequency, severity and development of
insured loss events arising out of catastrophes, as well as man-made disasters;
the outcome of our regular quarterly reserve review; the ability to exclude and
to reinsure the risk of loss from terrorism; fluctuations in interest rates;
returns on and fluctuations in the value of fixed-income investments, equity
investments and properties; fluctuations in foreign currency exchange rates;
rating agency actions; changes in laws and regulations and general competitive
factors, and other risks and uncertainties, including those detailed in the
Company's filings with the U.S. Securities and Exchange Commission and the SWX
Swiss Exchange. The Company does not assume any obligation to update any
forward-looking statements, whether as a result of new information, future
events or otherwise.

www.converium.com