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                                                                    EXHIBIT 10.2

                          REGISTRATION RIGHTS AGREEMENT

     This REGISTRATION RIGHTS AGREEMENT (this "Agreement"), dated as of June 21,
2001, is entered into between BIOPURE CORPORATION, a Delaware corporation (the
"Company"), and SOCIETE GENERALE, a bank organized under the laws of France (the
"Investor").

     WHEREAS, the Company and the Investor have entered into that certain Equity
Line Financing Agreement (the "Financing Agreement"), dated as of the date
hereof, pursuant to which the Company has agreed to issue and sell to the
Investor for an aggregate purchase price of up to $75,000,000 shares of Common
Stock, $0.01 par value per share (the "Common Stock"), from time to time as
provided in the Financing Agreement; and

     WHEREAS, pursuant to the terms of, and in partial consideration for, the
Investor's agreement to enter into the Financing Agreement, the Company has
agreed to provide the Investor with certain registration rights with respect to
the Common Stock issued under the Financing Agreement;

     NOW, THEREFORE, in consideration of the foregoing premises, the
representations, warranties, covenants and agreements contained herein and in
the Financing Agreement and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, intending to be
legally bound hereby, the parties hereto agree as follows:

                             ARTICLE I DEFINITIONS

     SECTION 1.1  DEFINITIONS. Capitalized terms used herein and defined in the
Financing Agreement shall have the same respective meanings herein as are
ascribed to them therein. In addition, the following terms shall have the
meanings ascribed to them below:

     "Investor" shall mean the Investor referenced in the preamble, and, unless
the context otherwise requires, shall include any assignee or transferee of the
Investor who becomes bound by this Agreement in accordance with Section 4.5
hereof.

     "Registrable Securities" means all of the shares of Common Stock issued
under the Financing Agreement until, (i) a registration statement under the
Securities Act covering the offer and sale of such shares of Common Stock has
been declared effective by the Commission and such shares of Common Stock have
been disposed of pursuant to such effective registration statement, (ii) such
shares of Common Stock are sold under circumstances in which all of the
applicable conditions of Rule 144 (or any similar provision then in force) under
the Securities Act ("Rule 144") are met, (iii) such shares of Common Stock have
been otherwise transferred and the Company has delivered a new certificate or
other evidence of ownership for such shares of Common Stock not bearing a
restrictive legend or (iv) such time as, in the opinion of counsel to the
Company, which counsel shall be reasonably acceptable to the Investor, such
Shares of Common Stock may be sold without any time, volume or manner limitation
pursuant to Rule 144(k) (or any similar provision then in effect) under the
Securities Act.


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     "Registration Statement" means the registration statement filed by the
Company pursuant to Section 2.1(a) and any additional registration statement
filed by the Company pursuant to Section 2.1(b).

     "Underwriter" means a securities dealer that purchases any Registrable
Securities as principal in an underwritten offering and not as part of such
dealer's market-making activities.

                         ARTICLE II REGISTRATION RIGHTS

     SECTION 2.1  REGISTRATION REQUIREMENTS. The Company shall use its
commercially reasonable efforts to effect the registration of the Registrable
Securities (including, without limitation, the execution of an undertaking to
file post-effective amendments, appropriate qualification under applicable blue
sky or other state securities laws and appropriate compliance with applicable
regulations issued under the Securities Act) as would permit or facilitate the
sale or distribution of all the Registrable Securities in the manner (including
manner of sale) and in all states reasonably requested by the Investor. Such
commercially reasonable efforts by the Company shall include the following:

          (a) The Company will as expeditiously as possible, prepare and file
with the Commission a registration statement (the "Registration Statement") on
Form S-3 (if use of such form is then available to the Company pursuant to the
rules of the Commission and, if not, on such other form promulgated by the
Commission for which the Company then qualifies and that counsel for the Company
shall deem appropriate and which form shall be available for the resale of the
Registrable Securities to be registered thereunder in accordance with the
provisions of this Agreement and in accordance with the intended method of
distribution of such Registrable Securities), and use its commercially
reasonable efforts to cause such filed Registration Statement to become
effective by the Effectiveness Deadline. The "Effectiveness Deadline" shall
mean, 180 days from the date of this Agreement. In the event the Registration
Statement shall not have been declared effective by the Commission by the
Effectiveness Deadline, the Investor shall have the right to terminate the
Financing Agreement. The Company will as expeditiously as possible prepare and
file with the Commission such amendments and supplements to the Registration
Statement and the prospectus used in connection therewith as may be necessary to
keep the Registration Statement effective for a period of not less than: (i) in
the case of a non-underwritten offering of Registrable Securities, until there
shall no longer be any Registrable Securities or (ii) with respect to an
underwritten offering of Registrable Securities, until the completion of the
distribution of Registrable Securities covered by the Registration Statement
(but not before the expiration of the period referred to in Section 4(3) of the
Securities Act and Rule 174 thereunder, if applicable), and the Company will
comply with the provisions of the Securities Act with respect to the disposition
of all securities covered by such Registration Statement during such period in
accordance with the intended methods of disposition by the Investor as set forth
in the Registration Statement.

          (b) The number of Registrable Securities covered by the initial
Registration Statement shall equal 3,000,000 shares. To the extent the Company
files an additional registration statement to cover Registrable Securities in
excess of the number of Registrable Securities covered by the initial
Registration Statement, such additional registration statement


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shall, for purposes of the Agreement (other than with respect to the
Effectiveness Deadline), also be deemed to be the "Registration Statement."

          (c) The Company will, prior to filing the Registration Statement or
prospectus or any amendment or supplement thereto, furnish to the Investor, its
counsel, and each Underwriter, if any, of the Registrable Securities covered by
such Registration Statement copies of such Registration Statement and prospectus
or any amendment or supplement thereto as proposed to be filed, together with
exhibits thereto, which documents will be subject to review and approval by the
foregoing persons (such approval not to be unreasonably withheld or delayed),
and thereafter furnish to the Investor, its counsel and each Underwriter, if any
such number of copies of such Registration Statement, each amendment and
supplement thereto (in each case including all exhibits thereto and documents
incorporated by reference therein), the prospectus included in such Registration
Statement (including each preliminary prospectus) and such other documents or
information as the Investor, its counsel or each Underwriter may reasonably
request in order to facilitate the disposition of the Registrable Securities.

          (d) The Company will use its commercially reasonable efforts to (i)
register or qualify such Registrable Securities under such other securities or
blue sky laws of such jurisdictions in the United States as the Investor may
reasonably (in light of its intended plan of distribution) request and (ii) if
applicable, cause such Registrable Securities to be registered with or approved
by such other governmental agencies or authorities in the United States as may
be necessary by virtue of the business and operations of the Company and do any
and all other acts and things that may be reasonably necessary or advisable to
enable the Investor to consummate the disposition of the Registrable Securities;
provided that the Company will not be required to (A) qualify generally to do
business in any jurisdiction where it would not otherwise be required to qualify
but for the fulfillment of its obligation under this paragraph (d), (B) subject
itself to taxation in any such jurisdiction or (C) consent or subject itself to
general service of process in any such jurisdiction.

          (e) The Company will promptly notify the Investor upon the occurrence
of any of the following events in respect of the Registration Statement or
related prospectus in respect of an offering of Registrable Securities: (i)
receipt of any request for additional information by the Commission or any other
federal or state governmental authority during the period of effectiveness of
the Registration Statement for amendments or supplements to the Registration
Statement or related prospectus; (ii) the issuance by the Commission or any
other federal or state governmental authority of any stop order suspending the
effectiveness of the Registration Statement or the initiation of any proceedings
for that purpose; (iii) receipt of any notification with respect to the
suspension of the qualification or exemption from qualification of any of the
Registrable Securities for sale in any jurisdiction or the initiation or
threatening of any proceeding for such purpose; (iv) the happening of any event
that makes any statement made in the Registration Statement or related
prospectus or any document incorporated or deemed to be incorporated therein by
reference untrue in any material respect or that requires the making of any
changes in the Registration Statement, related prospectus or documents so that
(or the Company otherwise becomes aware of any statement included in the
Registration Statement, related prospectus or documents that is untrue in any
material respect or that requires the making of any changes in the Registration
Statement, related prospectus or documents so that), in the case of the
Registration Statement, it will not contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or
necessary to make the statements therein not misleading, and that in the case of
the related prospectus, it will not contain any untrue statement of a material
fact or


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omit to state any material fact required to be stated therein or necessary to
make the statements therein, in the light of the circumstances under which they
were made, not misleading; and (v) the Company's reasonable determination that a
post-effective amendment to the Registration Statement would be appropriate (in
which event the Company will promptly make available to the Investor any such
supplement or amendment to the Registration Statement and, as applicable, the
related prospectus).

          (f) The Company will enter into customary agreements (including, if
applicable, an underwriting agreement in customary form and that is reasonably
satisfactory to the Company) and take such other actions as are reasonably
required in order to expedite or facilitate the disposition of the Registrable
Securities (the Investor may, at its option, require that any or all of the
representations, warranties and covenants of the Company to or for the benefit
of any applicable Underwriter also be made to and for the benefit of the
Investor).

          (g) The Company will make available to the Investor (and will deliver
to its counsel) and each Underwriter, if any, subject to restrictions imposed by
the United States federal government or any agency or instrumentality thereof,
copies of all correspondence between the Commission and the Company, its counsel
or auditors and will also make available, subject to restrictions imposed by the
United States federal government or any agency or instrumentality thereof, for
inspection by the Investor, its counsel, any Underwriter participating in any
disposition pursuant to a Registration Statement and any attorney, accountant or
other professional retained by the Investor or such Underwriter (collectively,
the "Inspectors"), all financial and other records, pertinent corporate
documents and properties of the Company (collectively, the "Records") as shall
be reasonably necessary to enable them to exercise their due diligence
responsibility, and cause the Company's officers and employees to supply all
information reasonably requested by any Inspectors in connection with the
Registration Statement. Records that the Company determines, in good faith, to
be confidential and that it notifies the Inspectors are confidential shall not
be disclosed by the Inspectors unless (i) the disclosure of such Records is
necessary in the reasonable opinion of the Inspectors to avoid or correct a
misstatement or omission in the Registration Statement or (ii) the disclosure or
release of such Records is required pursuant to a subpoena or other order from a
court of competent jurisdiction or governmental or administrative agency;
provided that prior to any disclosure or release pursuant to clause (ii), the
Inspectors shall provide the Company with prompt notice of any such request or
requirement so that the Company may seek an appropriate protective order or
waive such Inspectors' obligation not to disclose such Records; and, provided
further, that if failing the entry of a protective order or the waiver by the
Company permitting the disclosure or release of such Records, the Inspectors,
upon written advice of counsel, are compelled to disclose such Records, the
Inspectors may disclose that portion of the Records that counsel has advised the
Inspectors that the Inspectors are compelled to disclose. The Company may
require, as a condition to the disclosure to any Inspector of any confidential
information, that such Inspector execute and deliver to the Company a written
agreement, in form and substance reasonably satisfactory to the Company,
pursuant to which such Inspector agrees to the confidential treatment of such
information as contemplated above. The Investor agrees that information obtained
by it as a result of such inspections (not including any information obtained
from a third party who is not prohibited from providing such information by a
contractual, legal


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or fiduciary obligation to the Company) shall be deemed confidential and shall
not be used by it as the basis for any market transactions in the securities of
the Company or its Affiliates unless and until such information is made
generally available to the public. The Investor further agrees that it will,
upon learning that disclosure of such Records is sought in a court of competent
jurisdiction, give notice to the Company and allow the Company, at its expense,
to undertake appropriate action to prevent disclosure of the Records deemed
confidential.

          (h) In connection with an underwritten offering, the Company will
furnish to the Investor and to each Underwriter, if any, a signed counterpart,
addressed to the Investor and such Underwriter, of (1) such opinion or opinions
of counsel to the Company as may be required by an underwriting agreement in
customary form and (2) a comfort letter or comfort letters from the Company's
independent auditors in customary form and covering such matters of the type
customarily covered by comfort letters, as the Investor or the managing
Underwriter therefor reasonably requests pursuant to an underwriting agreement
in customary form. The Company also agrees to provide such comfort letters or
review letters from its independent auditors and such opinions of counsel to the
Company as are required by the Financing Agreement.

          (i) The Company will comply with all applicable rules and regulations
of the Commission, including, without limitation, compliance with applicable
reporting requirements under the Exchange Act, and will make available to its
security holders, as soon as reasonably practicable, an earning statement
covering a period of twelve (12) months, beginning within three (3) months after
the effective date of the Registration Statement, which earning statement shall
satisfy the provisions of Section 11(a) of the Securities Act.

          (j) The Company shall take all steps necessary to enable the Investor
to avail itself of the prospectus delivery mechanism set forth in Rule 153 (or
successor thereto) under the Securities Act, if available.

          (k) In connection with an underwritten offering, the Company will
cooperate, to the extent reasonably requested by the managing Underwriter for
the offering, in customary efforts to sell the securities under the offering,
including, without limitation, participating in "road shows" on a schedule as
shall be reasonably satisfactory to, and not unduly burdensome on, the Company;
provided that the Company shall not be obligated to participate in more than one
such offering in any twelve (12) -month period and any such participation by the
Company shall be at the expense of the managing Underwriter or the Investor
unless the Company shall also be offering securities in such underwritten
offering.

     The Company may require the Investor promptly to furnish in writing to the
Company such information regarding the intended methods of distribution of the
Registrable Securities as the Company may from time to time reasonably request
and such other information as may be legally required in connection with such
registration, including, without limitation, all such information as may be
requested by the Commission or the NASD or any state securities commission or
similar authority. If the Investor fails to provide such information requested
in connection with such registration within ten (10) business days after
receiving such written request, then the Company may cease pursuit of such
registration in respect of the Investor's Registrable Securities until such
information is provided.


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     The Investor agrees that, upon receipt of any notice from the Company of
the happening of any event of the kind described in Section 2.1(e) hereof, the
Investor will forthwith discontinue disposition of Registrable Securities
pursuant to the Registration Statement until the Investor's receipt of the
copies of the supplemented or amended prospectus contemplated by Section
2.1(e)(v) hereof, and, if so directed by the Company, the Investor will deliver
to the Company all copies, other than permanent file copies then in the
Investor's possession, of the most recent prospectus covering the Registrable
Securities at the time of receipt of such notice.

     SECTION 2.2  REGISTRATION EXPENSES. In connection with registration
hereunder, the Company shall pay the following registration expenses incurred in
connection therewith (the "Registration Expenses"): (i) all registration and
filing fees, (ii) fees and expenses of compliance with securities or blue sky
laws (including reasonable fees and disbursements of a single firm of counsel in
connection with blue sky qualifications of the Registrable Securities), (iii)
printing expenses, (iv) the Company's internal expenses (including, without
limitation, all salaries and expenses of its officers and employees performing
legal or accounting duties), (v) the fees and expenses incurred in connection
with the listing or quotation of the Registrable Securities, (vi) fees and
disbursements of counsel for the Company and customary fees and expenses for
independent auditors retained by the Company (including the expenses of any (A)
opinion letters or costs associated with delivery by counsel to the Company of
an opinion letter or opinion letters or (B) comfort letters or review letters or
costs associated with the delivery by independent auditors of comfort letters or
review letters, in each case required by or contemplated by Section 2.1(h)
hereof), and (vii) the fees and expenses of any special experts retained by the
Company in connection with such registration. The Company shall have no
obligation to pay any underwriting fees, discounts or commissions, or any
transfer taxes attributable to the sale of Registrable Securities, or the cost
of any special audit required by the Investor or any underwriter, such costs to
be borne by the Investor.

                  ARTICLE III INDEMNIFICATION AND CONTRIBUTION

     SECTION 3.1  INDEMNIFICATION BY THE COMPANY. The Company agrees to
indemnify and hold harmless the Investor, its partners, Affiliates, officers,
directors, employees and duly authorized agents, and each Person or entity, if
any, who controls the Investor within the meaning of Section 15 of the
Securities Act or Section 20 of the Exchange Act, together with the partners,
Affiliates, officers, directors, employees and duly authorized agents of such
controlling Person or entity (collectively, the "Controlling Persons"), from and
against any loss, claim, damage, liability, reasonable attorneys' fees, costs or
expenses and costs and expenses of investigating and defending any such claim
(collectively, "Damages"), and any action in respect thereof to which the
Investor, its partners, Affiliates, officers, directors, employees and duly
authorized agents, and any such Controlling Person may become subject under the
Securities Act or otherwise, insofar as such Damages (or proceedings in respect
thereof) arise out of, or are based upon, any untrue statement or alleged untrue
statement of a material fact contained in any Registration Statement or
prospectus relating to the Registrable Securities or any preliminary prospectus,
or arise out of, or are based upon, any omission or alleged omission to state
therein a material fact required to be stated therein or necessary to make the
statements therein (in the case of any prospectus or preliminary prospectus, in
light of the circumstances in which they were made) not misleading, except
insofar as the same are based upon information furnished in writing to the
Company by the Investor or an Underwriter expressly for use therein, and shall


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reimburse the Investor, its partners, Affiliates, officers, directors, employees
and duly authorized agents, and each such Controlling Person for any reasonable
legal and other expenses reasonably incurred by the Investor, its partners,
Affiliates, officers, directors, employees and duly authorized agents, or any
such Controlling Person in investigating or defending or preparing to defend
against any such Damages or proceedings as such expenses are incurred; provided,
however, that the Company shall not be liable to the Investor to the extent that
any such Damages arise out of or are based upon an untrue statement or omission
made in any preliminary prospectus if (i) the Investor failed to send or deliver
a copy of the final prospectus with or prior to the delivery of written
confirmation of the sale by the Investor to the Person asserting the claim from
which such Damages arise and (ii) the final prospectus would have corrected such
untrue statement or omission or alleged untrue statement or omission; provided
further, however, that the Company shall not be liable in any such case to the
extent that any such Damages arise out of or are based upon an untrue statement
or omission or alleged untrue statement or omission in any prospectus if (x)
such untrue statement or omission or alleged untrue statement or omission is
corrected in an amendment or supplement to such prospectus and (y) having
previously been furnished by or on behalf of the Company with copies of such
prospectus as so amended or supplemented, the Investor thereafter fails to
deliver such prospectus as so amended or supplemented prior to or concurrently
with the sale of a Registrable Security to the Person asserting the claim from
which such Damages arise. The Company also agrees to indemnify any Underwriters
of the Registrable Securities, their officers and directors and each Person who
controls such Underwriters on customary terms.

     SECTION 3.2  INDEMNIFICATION BY THE INVESTOR. The Investor, agrees to
indemnify and hold harmless the Company, its partners, Affiliates, officers,
directors, employees and duly authorized agents and each Person or entity, if
any, who controls the Company within the meaning of Section 15 of the Securities
Act or Section 20 of the Exchange Act, together with the partners, Affiliates,
officers, directors, employees and duly authorized agents of such controlling
Person, to the same extent as the foregoing indemnity from the Company to the
Investor, but only with reference to information related to the Investor or its
plan of distribution furnished in writing by the Investor or on the Investor's
behalf expressly for use in any registration statement or prospectus relating to
the Registrable Securities, or any amendment or supplement thereto, or any
preliminary prospectus. In case any action or proceeding shall be brought
against the Company or its partners, Affiliates, officers, directors, employees
or duly authorized agents or any such controlling Person or its partners,
Affiliates, officers, directors, employees or duly authorized agents, in respect
of which indemnity may be sought against the Investor, the Investor shall have
the rights and duties given to the Company, and the Company or its partners,
Affiliates, officers, directors, employees or duly authorized agents, or such
controlling Person, or its partners, Affiliates, officers, directors, employees
or duly authorized agents, shall have the comparable rights and duties given to
the Investor by Section 4.1. The Investor also agrees to indemnify and hold
harmless any Underwriters of the Registrable Securities, their officers and
directors and each Person who controls such Underwriters on customary terms with
reference to the same information as to which it agrees to indemnify the Company
referenced above. The Company shall be entitled to receive indemnities on
customary terms from Underwriters, selling brokers, dealer managers and similar
securities industry professionals participating in the distribution, to the same
extent as provided above, with respect to information so furnished in writing by
such persons specifically for inclusion in any prospectus or the Registration
Statement.


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     SECTION 3.3  CONDUCT OF INDEMNIFICATION PROCEEDINGS. Promptly after receipt
by any person or entity in respect of which indemnity may be sought pursuant to
Section 3.1 or 3.2 (an "Indemnified Party") of notice of any claim or the
commencement of any action, the Indemnified Party shall, if a claim in respect
thereof is to be made against the Person against whom such indemnity may be
sought (an "Indemnifying Party"), notify the Indemnifying Party in writing of
the claim or the commencement of such action; in the event an Indemnified Party
shall fail to give such notice as provided in this Section 3.3 and the
Indemnifying Party to whom notice was not given was unaware of the proceeding to
which such notice would have related and was materially prejudiced by the
failure to give such notice, the indemnification provided for in Section 3.1 or
3.2 shall be reduced to the extent of any actual prejudice resulting from such
failure to so notify the Indemnifying Party; provided, that the failure to
notify the Indemnifying Party shall not relieve it from any liability that it
may have to an Indemnified Party otherwise than under Section 4.1 or 4.2. If any
such claim or action shall be brought against an Indemnified Party, the
Indemnifying Party shall be entitled to participate therein, and, to the extent
that it wishes, jointly with any other similarly notified Indemnifying Party, to
assume the defense thereof with counsel reasonably satisfactory to the
Indemnified Party. After notice from the Indemnifying Party to the Indemnified
Party of its election to assume the defense of such claim or action, the
Indemnifying Party shall not be liable to the Indemnified Party for any legal or
other expenses subsequently incurred by the Indemnified Party in connection with
the defense thereof other than reasonable costs of investigation; provided that
the Indemnified Party shall have the right to employ separate counsel to
represent the Indemnified Party and its controlling persons who may be subject
to liability arising out of any claim in respect of which indemnity may be
sought by the Indemnified Party against the Indemnifying Party, but the fees and
expenses of such counsel shall be for the account of such Indemnified Party
unless (i) the Indemnifying Party and the Indemnified Party shall have mutually
agreed to the retention of such counsel or (ii) in the reasonable judgment of
the Company and such Indemnified Party, representation of both parties by the
same counsel would be inappropriate due to actual or potential conflicts of
interest between them, it being understood, however, that the Indemnifying Party
shall not, in connection with any one such claim or action or separate but
substantially similar or related claims or actions in the same jurisdiction
arising out of the same general allegations or circumstances, be liable for the
fees and expenses of more than one separate firm of attorneys (together with
appropriate local counsel) at any time for all Indemnified Parties or for fees
and expenses that are not reasonable. No Indemnifying Party shall, without the
prior written consent of the Indemnified Party, effect any settlement of any
claim or pending or threatened proceeding in respect of which the Indemnified
Party is or could have been a party and indemnity could have been sought
hereunder by such Indemnified Party unless such settlement includes an
unconditional release of such Indemnified Party from all liability arising out
of such claim or proceeding. Whether or not the defense of any claim or action
is assumed by an Indemnifying Party, such Indemnifying Party will not be subject
to any liability for any settlement made without its consent, which consent will
not be unreasonably withheld.

     SECTION 3.4  CONTRIBUTION. If the indemnification provided for in this
Article III is unavailable to the Indemnified Parties in respect of any Damages
referred to herein, then each Indemnifying Party, in lieu of indemnifying such
Indemnified Party, shall contribute to the amount paid or payable by such
Indemnified Party as a result of such Damages (i) as between the Company and the
Investor, on the one hand, and the Underwriters, on the other hand, in such
proportion as is appropriate to reflect the relative benefits received by the
Company and the


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Investor, on the one hand, and the Underwriters, on the other hand, from the
offering of the Registrable Securities, or if such allocation is not permitted
by applicable law, in such proportion as is appropriate to reflect not only the
relative benefits but also the relative fault of the Company and the Investor,
on the one hand, and of the Underwriters, on the other hand, in connection with
the statements or omissions that resulted in such Damages, as well as any other
relevant equitable considerations, and (ii) as between the Company, on the one
hand, and the Investor, on the other hand, in such proportion as is appropriate
to reflect the relative fault of the Company and of the Investor in connection
with such statements or omissions, as well as any other relevant equitable
considerations. The relative benefits received by the Company and the Investor,
on the one hand, and the Underwriters, on the other hand, shall be deemed to be
in the same proportion as the total proceeds from the offering (net of
underwriting discounts and commissions but before deducting expenses) received
by the Company and the Investor bear to the total underwriting discounts and
commissions received by the Underwriters, in each case as set forth in the table
on the cover page of the prospectus. The relative fault of the Company and the
Investor, on the one hand, and of the Underwriters, on the other hand, shall be
determined by reference to, among other things, whether the untrue or alleged
untrue statement of a material fact or the omission or alleged omission to state
a material fact relates to information supplied by the Company and the Investor
or by the Underwriters. The relative fault of the Company, on the one hand, and
of the Investor, on the other hand, shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by such party, and the parties' relative intent, knowledge,
access to information and opportunity to correct or prevent such statement or
omission.

     The Company and the Investor agree that it would not be just and equitable
if contribution pursuant to this Section 3.4 were determined by pro rata
allocation (even if the Underwriters were treated as one entity for such
purpose) or by any other method of allocation that does not take account of the
equitable considerations referred to in the immediately preceding paragraph. The
amount paid or payable by an Indemnified Party as a result of the Damages
referred to in the immediately preceding paragraph shall be deemed to include,
subject to the limitations set forth above, any legal or other expenses
reasonably incurred by such Indemnified Party in connection with investigating
or defending any such action or claim. Notwithstanding the provisions of this
Section 3.4, the Investor shall in no event be required to contribute any amount
in excess of the amount paid by the Investor for the Registrable Securities
(less underwriting discounts and commissions payable in connection with an
underwritten offering). No Person guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any Person who was not guilty of such fraudulent
misrepresentation. In connection with an underwritten offering, in the event of
an inconsistency between the terms of this Article III and the terms of the
underwriting agreement entered into among the Company, the Investor and the
underwriter, the terms of such underwriting agreement shall control.

                            ARTICLE IV MISCELLANEOUS

     SECTION 4.1  TERM. The registration rights provided to the holders of
Registrable Securities hereunder shall terminate on such date as there shall be
no Registrable Securities; provided, however, that the provisions of Article IV
hereof shall survive any


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termination of this Agreement. The Company may terminate this Agreement prior to
the issuance of any Registrable Securities at such time as the Financing
Agreement is terminated.

     SECTION 4.2  RULE 144. The Company covenants that it will file all reports
required to be filed by it under the Securities Act and the Exchange Act and
that it will take such further action as registered holders of Registrable
Securities may reasonably request, all to the extent required from time to time
to enable the Investor to sell Registrable Securities without registration under
the Securities Act within the limitation of the exemptions provided by (a) Rule
144, as such Rule may be amended from time to time, or (b) any similar rule or
regulation hereafter adopted by the Commission. If at any time the Company is
not required to file such reports, it will, upon the reasonable request of any
registered holder of Registrable Securities, make publicly available other
information so long as necessary to permit sales pursuant to Rule 144, within
the limitations of the exemption provided thereby. Upon the request of the
Investor, the Company will deliver to the Investor a written statement as to
whether it has complied with such requirements.

     SECTION 4.3  RESTRICTIONS ON SALE BY THE COMPANY AND OTHERS. If, and to the
extent, reasonably requested by the managing Underwriter or Underwriters in the
case of an underwritten public offering, that includes Registrable Securities as
contemplated by Section 2.1, the Company shall use commercially reasonable
efforts to cause its Affiliates to agree not to effect any public sale or
distribution of any securities similar to those being registered in accordance
with Section 2.1 hereof, or any securities convertible into or exchangeable or
exercisable for such securities, during the thirty (30) days prior to, and
during the period beginning on the effective date of the Registration Statement
(except as part of the Registration Statement) until all of the Registrable
Securities offered thereunder have been sold pursuant to such underwritten
public offering, provided, however, that such period shall not exceed ninety
(90) days.

     SECTION 4.4  AMENDMENT AND MODIFICATION. Any provision of this Agreement
may be waived, provided that such waiver is set forth in a writing executed by
the party against whom the enforcement of such waiver is sought. The provisions
of this Agreement, including the provisions of this sentence, may not be
amended, modified or supplemented, and waivers or consents to departures from
the provisions hereof may not be given, unless the Company has obtained the
written consent of the Investor. No course of dealing between or among any
Persons having any interest in this Agreement will be deemed effective to
modify, amend or discharge any part of this Agreement or any rights or
obligations of any Person under or by reason of this Agreement.

     SECTION 4.5  SUCCESSORS AND ASSIGNS; ENTIRE AGREEMENT. This Agreement and
all of the provisions hereof shall be binding upon and inure to the benefit of
the parties hereto and their respective successors and assigns; provided,
however, that the benefits and right contemplated hereunder to be provided to
any holder of Registrable Securities shall be limited to the registered holder
thereof. The Investor may assign its rights under this Agreement to any
subsequent holder of the Registrable Securities only with the consent of the
Company (which consent shall not be unreasonably withheld), provided that the
Company shall have the right to require any such subsequent holder of the
Registrable Securities to execute a counterpart of this Agreement as a condition
to such holder's claim to any rights hereunder. This Agreement,


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<PAGE>   11


together with the Financing Agreement, sets forth the entire agreement and
understanding between the parties as to the subject matter hereof and thereof
and merges and supersedes all prior discussions, agreements and understandings
(written or oral) of any and every nature between them with respect to such
subject matter.

     SECTION 4.6  SEPARABILITY. In the event that any provision of this
Agreement or the application of any provision hereof is declared to be illegal,
invalid or otherwise unenforceable by a court of competent jurisdiction, the
remainder of this Agreement shall not be affected except to the extent necessary
to delete such illegal, invalid or unenforceable provision unless that provision
held invalid shall substantially impair the benefits of the remaining portions
of this Agreement.

     SECTION 4.7  NOTICES. All notices, demands, requests, consents, approvals
or other communications required or permitted to be given hereunder or that are
given with respect to this Agreement shall be in writing and shall be personally
served or deposited in the mail, registered or certified, return receipt
requested, postage prepaid, or delivered by reputable air courier service with
charges prepaid, or transmitted by hand delivery, telegram, telex or facsimile,
addressed as set forth below, or to such other address as such party shall have
specified most recently by written notice: (i) if to the Company, to: Biopure
Corporation, 11 Hurley Street, Cambridge, MA, Attention: Francis H. Murphy,
Facsimile No.: (617) 234-6507, with copies (which shall not constitute notice)
to: LeBoeuf, Lamb, Greene & MacRae, 125 West 55th Street, New York, NY 10019,
Attention: Joseph Ferraro, Facsimile No. (212) 424-8500; and (ii) if to the
Investor, Societe Generale c/o SG Cowen Securities Corporation, 1221 Avenue of
the Americas, New York, NY 10020, Attention: Guillaume Pollet, Facsimile No.:
(212) 278-5467, with copies (which shall not constitute notice) to: Jones, Day,
Reavis & Pogue, 599 Lexington Avenue, New York, NY 10022, Attention: J. Eric
Maki, Facsimile (212) 755-7306. Notice shall be deemed given on the date of
service or transmission if personally served or transmitted by telegram, telex
or facsimile before the close of business on such date and on the next business
day if not served or transmitted by the close of business on such date. Notice
otherwise sent as provided herein shall be deemed given on the third business
day following the date mailed or on the next business day following delivery of
such notice by a reputable air courier service.

     SECTION 4.8  GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAW OF THE STATE OF NEW YORK, WITHOUT
GIVING EFFECT TO PRINCIPLES OF CONFLICTS OF LAWS THEREOF.

     SECTION 4.9  HEADINGS. The headings in this Agreement are for convenience
of reference only and shall not constitute a part of this Agreement, nor shall
they affect their meaning, construction or effect.

     SECTION 4.10  COUNTERPARTS. This Agreement may be executed in counterparts,
each of which shall be deemed to be an original instrument, and all of which
together shall constitute one and the same instrument.


                                       11
<PAGE>   12


     SECTION 4.11  FURTHER ASSURANCES. Each party shall cooperate and take such
action as may be reasonably requested by the other party in order to carry out
the provisions and purposes of this Agreement and the transactions contemplated
hereby.






                                       12



<PAGE>   13


     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by the undersigned, thereunto duly authorized, as of the date first set
forth above.

                                   BIOPURE CORPORATION

                                   By: /s/ Francis H. Murphy
                                      ----------------------------------
                                      Name:  Francis H. Murphy
                                      Title: CFO

                                   SOCIETE GENERALE

                                   By: /s/ Guillaume Pollet
                                      ----------------------------------
                                      Name:  Guillaume Pollet
                                      Title: Managing Director





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