EXHIBIT (2-3)









                            SHARE PURCHASE AGREEMENT




                                     BETWEEN



                  Unilabs Group Limited, British Virgin Islands



                Uniholding Corporation, United States of America



                            Unilabs S.A., Switzerland



                                       AND



                            KK Trust AG, Switzerland



                   Relating to 5% of the Shares of Unilabs SA










                                                          35







This Share Purchase  Agreement was entered into on February 17, 1997 between the
following parties:

1.       Unilabs Group Limited,           Road Town, Pasea Estate, P.O. Box
                                          3149, Tortola, British Virgin Islands

         (hereinafter referred to as "UGL")

                                                              of the first part

2.       UniHolding Corporation,          Delaware with its principal business
                                          address at 96 Spring Street, New
                                          York, N.Y. 10012, United States of
                                          America

(hereinafter referred to as "UHLD")

                                                             of the second part

3.       Unilabs SA,                     53, Avenue Blanc, 1202 Geneva,
                                         Switzerland

(hereinafter referred to as "the Company")

                                                              of the third part


                                       and

4.       KK Trust AG, Switzerland                    Grabenstrasse 32, 6301 Zug,
                                                     Switzerland

(hereinafter referred to as "Purchaser")

                                                             of the fourth part


Introduction

UGL is the  majority  shareholder  of  Unilabs  SA,  a  Swiss  corporation  (the
"Company"),  currently holding 79% of the Company's issued and outstanding share
capital.

UHLD is the sole shareholder of UGL.

The  Company  intends to do an initial  public  offering  ("IPO") by listing its
shares on the Swiss Stock  Exchange.  For  purposes of  preparing  the IPO,  the
Purchaser is prepared to buy an equity interest in the Company.




                                                          36





Based on the foregoing, the Parties agree as follows:

1.       Sale and Purchase of Shares

         UGL agrees to sell to the  Purchaser  and the  Purchaser  agrees to buy
         from UGL 800 bearer shares of the Company with a nominal value of Sfrs.
         500.-- each, representing 5% of the total of the issued and outstanding
         share capital of the Company.

         The 800 shares to be sold to the Purchaser are hereinafter  referred to
         as the "Shares".


2.       Purchase Price

         The purchase price for the Shares shall be Sfrs. [Confidential Portion]
         per share,  representing Sfrs.  [Confidential Portion] in the aggregate
         (the  "Purchase  Price").  The  Purchase  Price shall be payable at the
         Closing (as defined  under  Section 3.1 below) by wire  transfer to the
         account to be designated by UGL and against delivery of the Shares.

3.       Closing

3.1      Closing

         The sale and purchase of the Shares shall be consummated at the offices
         of Bar und Karrer, Seefeldstrasse 19, in Zurich, or at such other place
         as the  Parties  may agree,  no later than 3 days after the  conditions
         precedent  set forth in Section  3.2 below have been met (the  "Closing
         Date").  At the Closing the Purchaser shall execute by wire transfer to
         the account to be designated by UGL the Purchase Price against delivery
         of the Shares.

3.2      Conditions Precedent

         The  sale and  purchase  of the  Shares  contemplated  herein  shall be
         subject to the  following  conditions  being met on or before  February
         17th, 1997:

         a)       Sale  to  EIBA:  Confirmation  by UGL to  the  Purchaser  that
                  Eidgenossische   Bank  Beteiligungs-  und   Finanzgesellschaft
                  (hereinafter  "EIB") has on January  17,  1997  signed a Share
                  Purchase  Agreement  pursuant to which EIBA has acquired 5% of
                  the share capital of the Company.

         b)       Board Approval: Approval of the purchase of the Shares by
                  the board of directors of the Purchaser.



         c)       Board Approvals: Approval of the purchase of the Shares

                                                          37





                  by the boards of directors of UGL, the Company and UHLD.

         d)       EIBA Approval:             Approval of EIBA of this Agreement.

4.       Representations and Warranties of Seller and Company

         UGL,  the  Company and UHLD hereby  represent  and warrant  jointly and
         severally to the Purchaser,  such  representations and warranties to be
         true as of the signing of this Agreement and at Closing, the following:

         a)       Legal Existence:                   The Company and each of its
                  ---------------
                  subsidiaries listed in Exhibit 1 (the "Subsidiaries") is
                                         ---------
                  a corporation duly incorporated and validly existing under the
                  laws of the jurisdiction in which it is incorporated,  capable
                  of being sued in its own right.  The  Company has the power to
                  own its property and assets and the  authority to carry on its
                  business as currently conducted.

         b)       Ownership Structure:  The Company has a share capital of
                  Sfrs. 8,000,000.--, divided into 16,000 shares with a
                  nominal value of Sfrs. 500.-- each.  No further capital,
                  non-voting stock, convertible securities or similar
                  rights in the Company have been or will by the Closing be
                  created or issued or agreed to be issued.  The Shares
                  have been validly issued and fully paid-up.

                  Notwithstanding   the  foregoing,   a  restructuring   of  the
                  Company's  share capital is currently  contemplated in view of
                  the IPO which will result in (i) a split of the nominal  value
                  of the bearer shares from Sfrs.  500.-- to Sfrs 40.-- and (ii)
                  the creation of a new class of registered shares of Sfrs 20.--
                  nominal  value  which will  represent  30% of the  capital and
                  approximately 47% of the voting rights.  The registered shares
                  will be reserved to UGL and the  Purchaser  will  receive only
                  bearer shares after the  restructuring.  This proposal for the
                  Company's new dual capital structure is shown in Exhibit 2.

         c)       Ownership.  The Seller is the sole legal and beneficial
                  owner of the Shares, free and clear of all liens,
                  encumbrances, options, charges and other claims arising
                  from any privilege, pledge or security arrangement.  The
                  Seller has full right and capacity to transfer and sell
                  the Shares.

                  Upon delivery of the Shares,  the Purchaser  will receive good
                  and valid  title to the  Shares,  free and clear of all liens,
                  encumbrances or other rights of third parties.  On the Closing
                  Date,  the  ownership  structure  of the  Company  will  be as
                  follows:



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                                                                   % of capital

                           Unilabs Group Ltd.:                            74.0%
                           Unilabs Holding SA, Panama:                    10.0%
                           EIBA:                                           5.0%
                           KK Trust AG:                                    5.0%
                           Banque Cantonale de Geneve.:                    5.0%
                           Third Party                                     1.0%


         d)       Annual Accounts:  The latest  consolidated  annual accounts as
                  per  May  31,  1996  of  the  Company  (as  delivered  to  the
                  Purchaser)   fairly  represent  the   consolidated   financial
                  situation  of the  Company as per the  balance  sheet date and
                  have been  prepared  in  compliance  with  generally  accepted
                  accounting  principles  as applied  in the  United  States (US
                  GAAP).

         e)       Assets:  Except as disclosed in Exhibit 3, the Company
                  ------                          ---------
                  and each of the Subsidiaries owns all real property,  personal
                  property and other assets, tangible and intangible,  reflected
                  in the  latest  annual  balance  sheet of the  Company  or the
                  relevant  subsidiary,  free and clear of all  liens,  charges,
                  security interest and other encumbrances.  There are no assets
                  which are used in the  conduct of the  business of the Company
                  or any of its  Subsidiaries  which  are not  reflected  in the
                  latest  annual  balance  sheet of the Company or the  relevant
                  Subsidiary.

         f)       Accounts Receivable:  The accounts receivable reflected in the
                  latest annual  accounts of the Company and of each  Subsidiary
                  are fully  collectible  within 90 days and, to the extent they
                  are not fully  collectible,  whether or not within a period of
                  90 days,  the Company or the relevant  Subsidiary  has created
                  provisions sufficient to cover any shortfall.

         g)       No Undisclosed Liabilities:  Except as disclosed in
                  Exhibit 4, none of the Company and the Subsidiaries have
                  any liabilities or obligations of any nature (absolute,
                  accrued, contingent or otherwise), which are not fully
                  reflected or reserved against in the latest annual
                  accounts of the Company or the relevant Subsidiary.

         h)       Books and Records:  The Company and each Subsidiary is in
                  possession and has accurately kept all accounts, books,
                  letters, financial and other records as required by
                  applicable law.

         i)       Taxes:  The Company and each Subsidiary has timely filed
                  all tax returns for income tax, withholding taxes, stamp
                  taxes, sales taxes, social security taxes and all other
                  taxes of every kind whatsoever required by law to be
                  filed and all such tax returns are complete and accurate.

                                                          39





                  The Company and each  Subsidiary has paid all taxes which have
                  become due and there is no further liability for any taxes and
                  no  interests or  penalties  accrued or accruing  with respect
                  thereto which would exceed the provisions  created in the last
                  balance  sheet  of  the  Company  or the  relevant  Subsidiary
                  specifically for such liabilities, interests or penalties.

         j)       No Material Adverse Change:  Except as disclosed in
                  Exhibit 5, attached hereto, since the last balance sheet
                  date of May 31, 1996, the financial situation
                  (consolidated and non-consolidated) of the Company or its
                  business has not been affected by any material adverse
                  change.

         k)       Permits and Authorizations:  The Company and each
                  Subsidiary has all the permits and authorizations which
                  are necessary to carry on its business and neither the
                  execution of this Agreement nor the consummation of the
                  transaction contemplated herein will affect the
                  effectiveness of such permits and authorizations.

         l)       Compliance with Applicable Laws:  In conducting its
                  business  as  currently   conducted,   the  Company  and  each
                  Subsidiary  is  in  compliance   with  all  applicable   laws,
                  statutes,  orders,  rules and regulations of any  governmental
                  authority.  Without  limiting the generality of the foregoing,
                  the  Company and each  Subsidiary  is in  compliance  with all
                  environmental laws, regulations, orders and decrees applicable
                  to it.

         m)       Insurance:  The insurance policies of the Company and of
                  each Subsidiary adequately cover the risks associated
                  with the business of the Company and the relevant
                  Subsidiary.

         n)       Intellectual Property Rights:  The Company and each
                  Subsidiary   owns  all  the  knowhow,   patents,   trademarks,
                  copyrights and other  intellectual  property  rights,  if any,
                  which are necessary for or used in the conduct of its business
                  as it is now being  conducted or has adequate  license to such
                  rights. None of such patents, trademarks,  copyrights or other
                  intellectual  property  rights violate the rights of any third
                  party.



         o)       Information Technology:  The Company and each Subsidiary
                  has the rights to the information technology necessary to
                  conduct the business as currently conducted and such
                  rights will continue to be effective at least until
                  December 31, 1998.  Exhibit 6 contains a complete list of
                  information technology rights (licenses, source codes,
                  etc.) currently used by the Company and the Subsidiaries.

                                                          40





         p)       No Litigation:  No litigation, arbitration,
                  administrative  proceedings  (including  tax  proceedings)  or
                  governmental or regulatory  investigations  are pending or, to
                  the best of the  Company's or Seller's  knowledge,  threatened
                  against  the  Company  or  any  Subsidiary  and  there  are no
                  judgments or decisions which could  jeopardize the conclusion,
                  performance or enforceability of this Agreement or which could
                  otherwise adversely affect this Agreement.

         q)       Group Structure:  The group structure shown in Exhibit 1
                  is complete and accurate; except with respect to Vivagen
                  Diagnostics AG and SQ-Lab Aerztelabor AG, the share
                  capital of each group company is fully paid-in.

         r)       Intercompany Dealings:  Except as disclosed to the
                  Purchaser in Exhibit 7, all intercompany dealings between
                  companies of the group shown in Exhibit 1 or between
                  group companies and related parties have been made at
                  market conditions (arm's length).

         s)       Full Disclosure:         The information and material provided
                  by the company to the  Purchaser  is complete  and accurate in
                  every material  respect and no  information  has been withheld
                  from the  Purchaser  which would have affected its decision to
                  enter into this Agreement.  Without limiting the generality of
                  the foregoing,  there are no oral or written  agreements  that
                  have not been  disclosed  to the  Purchaser  and  which  could
                  affect  the  present  or  future  ownership  structure  of the
                  Company.

5.       Remedies

5.1      Term of Representations and Warranties

         The  representations  and  warranties  set  forth in  Section 4 of this
         Agreement  shall  continue to be in effect until  February  1st,  2000.
         Notice of claims may be given by the  Purchaser  in  writing  until and
         including February 1st, 2000.

         The Purchaser is not bound by any  examination  or notice  requirements
         otherwise  applicable  under Swiss law, except that upon discovery of a
         claim notice  shall be given by the  Purchaser to the Seller as soon as
         reasonably practicable,  subject to the overall limitation provided for
         in the preceding paragraph.

5.2      Remedies

         In case of a breach of a  representation  and warranty UGL, the Company
         and UHLD  shall be  jointly  and  severally  liable  to  indemnify  the
         Purchaser  against all losses  suffered by the Purchaser as a result of
         any such  misrepresentations or breach of warranty or covenant. In case
         of a breach of

                                                          41





         representations and warranties,  the losses are calculated based on the
         difference  between  the actual net asset  value of the  Company,  on a
         consolidated basis, and the consolidated net asset value of the Company
         had the relevant representation and warranty been accurate.

         Recession  of  this  agreement  and  unwinding  of the  transaction  in
         accordance with "Article 208 du Code des Obligations" are excluded.

5.3      Limitation

         No claims may be raised by the Purchaser under Section 5 of
         this Agreement, unless such claims in each single case of
         breach of warranty exceed Sfrs. 50'000.-- and, in the
         aggregate, reach an amount of Sfrs. 100'000.--.  For the
         avoidance of doubt, if the claim of the Purchaser exceeds in
         the aggregate Sfrs. 100'000.--, the Purchaser is entitled to
         claim the entire amount and not only the amount in excess of
         Sfrs. 100'000.--.

6.       Sale in and after IPO

         The Purchaser  shall have the right to sell any or all of its shares to
         the  public in the event of an IPO as from the first day of  trading on
         the Swiss  Exchange.  The sale of the shares in an IPO shall take place
         at the terms and conditions set by all the parties involved in the IPO.
         Such right shall be subordinated to a preference  right granted to EIBA
         pursuant  to a  Shareholders  Agreement  dated  January 17, 1997 by and
         between EIBA, UGL and the Company.

         To enable the  Purchaser  to exercise  its right to sell in an IPO, UGL
         shall  promptly  indicate  to the  Purchaser  in writing  the terms and
         conditions at which the IPO is to take place. Within five business days
         of receipt of such information,  the Purchaser shall notify UGL whether
         or not it wishes to exercise its right at the terms  indicated.  If so,
         the  Purchaser  shall deliver its shares in the Company to the Company,
         or a  party  designated  by the  Company,  against  payment  of the IPO
         placement price.



7.       Puts and Calls

7.1      Call Option of the Seller

         For the period of January 1, 1998 to December  31, 2001 UGL, or a party
         designated  by UGL,  shall  have the right to  purchase  the  Company's
         shares then held by the Purchaser. The exercise price shall be equal to
         the purchase price paid by the Purchaser pursuant to the Share Purchase
         Agreement   increased  by  20%  per  annum,   compounded  annually  and
         calculated for the

                                                          42





         period  between  payment of the  purchase  price by the  Purchaser  and
         exercise of the call option by UGL.

         If UGL  wishes  to  exercise  its  call  option,  it shall  notify  the
         Purchaser  in writing no later than by 12.00 noon on December 31, 2001.
         If such  date is not a date on which  banks  are open for  business  in
         Zurich,  the exercise notice shall reach the Purchaser by 12.00 noon on
         the last  business day of 2001.  The sale shall be completed  within 10
         business  days of receipt of the exercise  notice by the  Purchaser and
         shall take place by the Purchaser  delivering its shares in the Company
         to UGL or its  designee  against  receipt of the exercise  price.  Each
         party shall bear its own costs and expenses incurred in connection with
         the exercise of the call option.

         Notwithstanding  the above, UGL hereby commits not to exercise its call
         option  as long as EIBA's  put  option  against  UGL,  pursuant  to its
         Shareholders Agreement dated January 17, 1997, has not expired.

7.2      Put Option for the Purchaser

         For the period of February  1st,  2000 until  December  31st,  2001, or
         immediately  if UGL breaches  Sec.  8.4, the  Purchaser  shall have the
         right to sell its shares in the Company to one of the following parties
         (in that order of priority):  first,  to UGL,  second,  if UGL fails to
         fulfill its purchase obligation under this Sec. 7.2, within twenty days
         of  notification  by the Purchaser,  to the Company,  and third, if the
         company  fails to fulfill its purchase  obligation  under this Sec. 7.2
         within twenty days of notification by the purchaser, to UHLD.

         The  exercise  price for the put option  shall be equal to the purchase
         price paid by the Purchaser  pursuant to the Share Purchase  Agreement,
         increased by 12% per annum  compounded  annually and calculated for the
         period  between the date of purchase by the  Purchaser  and the date of
         exercise of the put option by the Purchaser.

         If the Purchaser  wishes to exercise its put option it shall notify the
         party concerned in writing, indicating that it exercises its put option
         and the exercise price.  The sale shall be completed within 10 business
         days of receipt of the exercise notice by the party concerned and shall
         take  place by the  Purchaser  delivering  its  shares  in the  Company
         against  receipt of the exercise  price.  Each party shall bear its own
         costs and expenses incurred in connection with the exercise of the call
         option.

7.3      Subordination of Put

         The Purchaser hereby expressly  acknowledges that any claim it may have
         against UGL and/or the Company pursuant to section

                                                          43





         7.2 above will be  subordinated  to any claim made by EIBA  against UGL
         and/or the Company in connection with EIBA's put option pursuant to its
         Shareholders  Agreement  dated  January 17,  1997,  so that UGL, or the
         Company, as the case may be, shall first perform the put option of EIBA
         before performing the put option of the Purchaser.

         Notwithstanding  the  foregoing,  if EIBA,  does not  exercise  its put
         option  within ten days after having  received  notice of the Purchaser
         that the  Purchaser  exercises  its put option,  UGL or the Company can
         perform the put option of the Purchaser.

7.4      Expiration of Puts and Calls

         It is agreed that both the call  option of UGL  pursuant to Section 7.1
         above and the put option of the Purchaser pursuant to Section 7.2 above
         shall  cease to be valid if an IPO of the  Company  occurs at the first
         day of trading on the Swiss Exchange, provided that at least 35% of the
         Company's shares have been placed with the public.

8.       Miscellaneous

8.1      Cost and Expenses

         Each Party shall pay its own legal fees, costs,  traveling expenses and
         other expenses in connection with this transaction.

8.2      Taxes

         Each party shall bear all taxes or other  charges  which  become due by
         itself  in  connection  with  the  execution  or  performance  of  this
         Agreement, such as securities transfer tax.

8.3      Access to Information

         The company  grants the Purchaser  full access to, and provide it with,
         all information and material regarding the ownership  structure and the
         business of the company and its  subsidiaries  which the  Purchaser may
         reasonably request. In particular,  the Seller shall keep the Purchaser
         duly  informed  of the IPO  process.  This right of  information  is in
         addition to the statutory  right of  information  of the Purchaser as a
         shareholder  of the  Company.  The  Purchaser  undertakes  to keep such
         information  confidential  and not to  disclose  it to any third  party
         unless  required  to do so by  law,  a  recognized  stock  exchange  or
         pursuant to an order of a competent governmental authority or court.

8.4      Transfer Restrictions

         For the term of this  Agreement,  UGL shall not be  permitted  to sell,
         assign or otherwise transfer its controlling

                                                          44





         shareholding  interest in the Company without the prior written consent
         of the  Purchaser.  In the  event  the  transfer  of UGL's  controlling
         interest  in the  Company is to be made to another  company  within the
         same group of companies,  the Purchaser will not unreasonably  withhold
         such consent,  provided the transferee  agrees to be bound by the terms
         of this Agreement.

8.5      Representation on Company's Board

         In the event EIBA ceases to be represented on the board of the Company,
         the Purchaser  shall have the right to be  represented  on the board of
         directors  of the  Company.  For  this  purpose,  the  Purchaser  shall
         nominate  a  person  who  shall be  elected  by the  Company's  general
         shareholders'  meeting  to  the  Company's  board  of  directors.   UGL
         undertakes  to cast its vote at such general  shareholders'  meeting in
         support of the election of the person nominated by the Purchaser.

8.6      Notices

         Communications under this Agreement shall be made in writing by letter,
         telex or telefax and addressed as follows:

         if to the Purchaser:

         K K Trust AG
         Grabenstrasse 32
         6301 Zug

         Tel.:  +41-711 4161
         Fax :  +41-711 4281

         if to UGL, the Company or UHLD:

         Unilabs SA
         Mr. Eric Wavre
         12, place Cornavin
         1 2 01 Geneva
         Tel:  +41-22-909-7777
         Fax:  +41-22-909-7707

8.7      Entire Agreement

         This Agreement embodies the entire agreement between the parties hereto
         with respect to the transaction contemplated herein and there have been
         and are no  agreements  or  warranties  between the parties  other than
         those set forth or provided for herein.  This  Agreement may be amended
         only in writing through an instrument signed by all the parties hereto.

8.8      Confidentiality

         The Parties  hereto agree and  undertake to keep the terms and contents
         of this Agreement strictly confidential and not to

                                                          45





         disclose any related  information  to any third party without a written
         consent  of the  other  Parties,  unless  required  to do so by law,  a
         recognized  stock  exchange  or  pursuant  to an order  of a  competent
         governmental  authority of court.  In such an event the Party concerned
         shall inform the other Parties of such disclosure.

8.9      Governing Law and Jurisdiction

         This Agreement shall be governed by Swiss law.  Disputes arising out of
         or in  connection  with  this  Agreement  shall  be  submitted  to  the
         jurisdiction  of the ordinary courts of Canton of Zug, venue being Zug.
         The Purchaser  reserves the right to take legal action against UGL, the
         Company or UHLD at their  registered  offices or at any other competent
         place of jurisdiction.



                                                          46





         Place and Date:

         ----------------------                       ------------------------
         UNILABS GROUP LTD.                           K K TRUST AG




         ----------------------
         UNILABS SA




         -----------------------
         UNIHOLDING CORPORATION






                                                          47




                                List of Exhibits



Exhibit 1:                 Structure of the Unilabs SA group.

Exhibit 2:                 Proposal for Unilabs SA's new dual capital
                           structure.

Exhibit 3:                 List of assets not owned or not free and clear

Exhibit 4:                 List of interest bearing debts and contingent
                           liabilities

Exhibit 5:                 Material adverse change

Exhibit 6:                 List of information technology rights

Exhibit 7:                 List of intercompany transactions and transactions
                           with related parties