Exhibit 99.1

                               [GRAPHIC OMITTED]
                             Fresenius Medical Care


                                 PRESS RELEASE




                                                   
      Contact:                                        Contact:
      Oliver Maier                                    Heinz Schmidt
      Sr. V.P. Investor Relations & Communications    Vice President Investor Relations
      Phone:    + 49 6172 609 2601                    Phone:  1- 781 402 4518
      Fax:      + 49 6172 609 2301                    Fax:    1- 781 402 9741
      E-mail:   ir-fms@fmc-ag.com                     E-mail: ir-fmcna@fmc-ag.com
                -----------------                             -------------------
      Internet: http://www.fmc-ag.com
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           FRESENIUS MEDICAL CARE NORTH AMERICA ANNOUNCES EXTENSION OF
      EXPIRATION DATE FOR TENDER OFFER AND CONSENT SOLICITATION FOR THE 9%
               SENIOR SUBORDINATED NOTES OF RENAL CARE GROUP, INC.


Lexington, Massachusetts - December 23, 2005 - Fresenius Medical Care North
America today announced that, in connection with the previously announced tender
offer and consent solicitation by Florence Acquisition, Inc. ("Florence"), an
indirect subsidiary of Fresenius Medical Care AG (Frankfurt Stock Exchange: FME,
FME3) (NYSE: FMS, FMS-p) ("FMC-AG"), for any and all of the $159,685,000 in
outstanding principal amount of 9% Senior Subordinated Notes Due 2011 (the
"Notes") of Renal Care Group, Inc., Florence is extending the tender offer
expiration date to 5:00 p.m., New York City time, on January 30, 2006.

        As previously announced, the total consideration to be paid for validly
tendered and accepted Notes would have been $1,112.16 per $1,000 principal
amount of the Notes, calculated on the basis of the yield to maturity on the
4.25% U.S. Treasury Note due October 31, 2007 (the "Reference Security") as of
10:00 a.m., New York City time, on the price determination date of December 14,
2005, assuming the payment date for the tender offer was December 30, 2005.
Pursuant to the terms of the tender offer, as a result of the extension of the
expiration date to January 30, 2006, the total consideration will be calculated
using a new price determination date of January 13, 2006, which is the tenth
business day preceding the scheduled expiration date. The total consideration to
be paid will be recalculated using the yield to maturity on the Reference
Security as of 10:00 a.m., New York City time, on January 13, 2006.

Fresenius Medical Care North America,
95 Hayden Avenue, Lexington, MA 02420-9192                           Page 1 of 3


        As of 5:00 p.m., New York City time, on December 22, 2005, 99.87% of the
outstanding aggregate principal amount of the Notes have been tendered. Holders
who have already tendered their Notes and delivered their consents may no longer
withdraw their Notes or revoke their consents.

        Except as set forth above, all other provisions of the tender offer and
consent solicitation with respect to the Notes are as set forth in the Offer to
Purchase and Consent Solicitation Statement, dated November 30, 2005 (the "Offer
to Purchase"). Florence reserves the right to further amend the tender offer and
the consent solicitation in its sole discretion. As previously announced, the
offer to purchase the Notes is being made in connection with the pending
acquisition of Renal Care Group, Inc. and its subsidiaries by FMC-AG (the
"Merger"). The consummation of Florence's tender offer is conditioned on, among
other things, the satisfaction of the closing conditions to the Merger as set
forth in the merger agreement.

        Credit Suisse First Boston LLC is acting as Dealer Manager for the
tender offer and as Solicitation Agent for the consent solicitation and can be
contacted at (212) 538-0652 (collect) or (800) 820-1653 (toll free). Morrow &
Co., Inc. is the Information Agent and can be contacted at (203) 658-9400
(collect) or (800) 607-0088 (toll free). Questions about the tender offer and
consent solicitation may be directed to the Dealer Manager, and requests for
copies of the related documents may be directed to the Information Agent.

        This release is not an offer to purchase, a solicitation of an offer to
purchase or a solicitation of consent of any Notes. The tender offer and the
consent solicitation are being made solely by the Offer to Purchase.


Fresenius Medical Care North America,
95 Hayden Avenue, Lexington, MA 02420-9192                           Page 2 of 3


        FMC-AG is the world's largest integrated provider of products and
services for individuals undergoing dialysis because of chronic kidney failure,
a condition that affects more than 1,300,000 individuals worldwide. Through its
network of approximately 1,670 dialysis clinics in North America, Europe, Latin
America, Asia-Pacific and Africa, FMC-AG provides dialysis treatment to
approximately 130,400 patients around the globe. FMC-AG is also the world's
leading provider of dialysis products, such as hemodialysis machines, dialyzers
and related disposable products.

        This release contains forward-looking statements that are subject to
various risks and uncertainties. Actual results could differ materially from
those described in these forward-looking statement due to certain factors,
including changes in business, economic and competitive conditions, regulatory
reforms, foreign exchange rate fluctuations, uncertainties in litigation or
investigative proceedings, and the availability of financing. These and other
risks and uncertainties are detailed in FMC-AG's reports filed with the U.S.
Securities and Exchange Commission. FMC-AG does not undertake any responsibility
to update the forwarding-looking statements in this release.

                                     --END--

Fresenius Medical Care North America,
95 Hayden Avenue, Lexington, MA 02420-9192                           Page 3 of 3