Exhibit 4.6

                          REGISTRATION RIGHTS AGREEMENT

                                                                 August 15, 1997

To each of the persons 
named on Schedule I hereto:

Dear Sirs:

      This will confirm that, in consideration of the consummation of the merger
of BICHART Acquisition Corp. ("Acquisition"), a wholly-owned subsidiary of The
BISYS Group, Inc. (the "Company"), with and into Charter Systems, Inc.
("Charter"), pursuant to the Agreement and Plan of Merger dated as of August 5,
1997 among the Company, Acquisition, Charter and the shareholders of Charter
named therein, in which an aggregate number of shares of Common Stock, $.02 par
value, of the Company (the "Shares"), set forth on Schedule I hereto opposite
your name will be issuable to you upon conversion of shares of common stock, par
value $.01 per share, of Charter, Series C Convertible Preferred Stock, par
value $.01 per share, of Charter and/or Series E Convertible Preferred Stock,
par value $.01 per share, of Charter held by you, the Company hereby covenants
and agrees with each of you, as follows:

      1. Certain Definitions. As used herein, the following terms shall have the
following respective meanings:

            "Commission" shall mean the Securities and Exchange Commission, or
      any other federal agency at the time administering the Securities Act.

            "Common Stock" shall mean the Common Stock, $.02 par value, of the
      Company, as constituted as of the date of this Agreement.

            "Distribution Period" shall mean the period commencing upon the
      termination of the restrictions imposed by Section 7.11 of the Merger
      Agreement and ending on the earlier to occur of (i) the sale by the
      holders of Registerable Stock of all of the Registerable Stock covered by
      the registration statement referred to in Sections 2 and 3 below or (ii)
      the second anniversary of the Effective Time.

            "Effective Time" shall mean the Effective Time of the Merger, as
      defined in the Merger Agreement.


            "Exchange Act" shall mean the Securities Exchange Act of 1934 or any
      similar federal statute, and the rules and regulations of the Commission
      thereunder, all as the same shall be in effect at the time.

            "Merger" shall mean the merger of Acquisition with and into Charter
      pursuant to the Merger Agreement.

            "Merger Agreement" shall mean the Agreement and Plan of Merger dated
      as of August __, 1997 among the Company, Acquisition, Charter and the
      shareholders of Charter named therein.

            "Registerable Stock" shall mean any shares of Common Stock issued to
      you in the Merger, and not transferred or otherwise disposed of by you.

            "Securities Act" shall mean the Securities Act of 1933, as amended,
      or any similar federal statute, and the rules and regulations of the
      Commission thereunder, all as the same shall be in effect at the time.

      2. Registration of Registerable Stock.

      Promptly after the Effective Time, the Company shall use its best efforts
to register under the Securities Act for public sale by the Holders of shares of
Registerable Stock the shares of Registerable Stock held by them. The Company
shall not be obligated to effect registration of Registerable Stock pursuant to
this Section 2 on more than one occasion.

      3. Registration Procedures. The Company will, as expeditiously as
practicable after the Effective Time:

            (a) prepare, submit to you and to one counsel for the selling
      shareholders for a reasonable opportunity to review not more than thirty
      (30) days after the Effective Time, and thereafter file with the
      Commission, as soon as practicable, a registration statement with respect
      to such securities (which shall be on Form S-3 if the Company is then
      eligible to use such form and otherwise on Form S-1 or such other form of
      general applicability acceptable to the Company), and shall use its best
      efforts to cause such registration statement to become and remain
      effective during the Distribution Period;


                                       2


            (b) prepare and file with the Commission such amendments and
      supplements to such registration statement and the prospectus used in
      connection therewith as may be necessary to keep such registration
      statement effective during the Distribution Period;

            (c) furnish to each seller such number of copies of the registration
      statement and the prospectus included therein (including each preliminary
      prospectus) and any amendment or supplement thereto as such person may
      reasonably request in order to facilitate the public sale of the
      Registerable Stock covered by such registration statement;

            (d) use its best efforts to register or qualify the Registerable
      Stock covered by such registration statement under the securities or blue
      sky laws of a reasonable number of jurisdictions (provided that the
      Company will not be required to (i) qualify generally to do business in
      any jurisdiction where it would not otherwise be required to qualify but
      for this paragraph (d), (ii) subject itself to taxation in any such
      jurisdiction or (iii) consent to general service of process in any
      jurisdiction):

            (e) promptly notify each seller of Registerable Stock and (if
      requested by any such seller) confirm such notice in writing, (i) when
      such registration statement or any amendment or supplement thereto or to
      the prospectus or preliminary prospectus contained therein has been filed,
      (ii) of any request by the Commission for amendments or supplements to
      such registration statement or prospectus or for additional information,
      (iii) of the issuance by the Commission of any stop order suspending the
      effectiveness of such registration statement or the initiation of
      proceedings for that purpose, or (iv) of the receipt by the Company of any
      notification with respect to the suspension of the qualification of the
      Registerable Stock for sale in any jurisdiction or the initiation or
      threatening of any proceeding for that purpose;

            (f) immediately notify each seller under such registration
      statement, at any time when a prospectus relating thereto is required to
      be delivered under the Securities Act, of the happening of any event as a
      result of which the prospectus contained in such registration statement,
      as then in effect, includes an untrue statement of a material fact or
      omits to state any material fact required to be stated therein or
      necessary to make the statements therein not misleading 


                                       3


      in the light of the circumstances then existing, and promptly thereafter
      prepare and file with the Commission a supplement or amendment to such
      prospectus, such registration statement or any document incorporated
      therein by reference, or make such other filing, such that as thereafter
      delivered to the purchasers of Registerable Stock, the prospectus will not
      contain an untrue statement of material fact or omit to state any material
      fact necessary to make the statements therein not misleading;

            (g) use its best efforts to obtain the withdrawal of any order
      suspending the effectiveness of such registration statement;

            (h) make available for inspection by each seller, and any attorney,
      accountant or other agent retained by such seller, all financial and other
      records, pertinent corporate documents and properties of the Company, and
      cause the Company's officers, directors and employees to supply all
      information reasonably requested by any such seller, attorney, accountant
      or agent in connection with such registration statement and permit such
      seller, attorney, accountant or agent to review and comment on such
      registration statement.

      In connection with each registration hereunder, each selling holder of
Registerable Stock shall furnish to the Company in writing such information with
respect to himself and the proposed distribution by him as shall be reasonably
necessary in order to assure compliance with federal and applicable state
securities laws.

      4. Expenses. All expenses incurred by the Company in complying with
Sections 2 and 3 hereof, including, without limitation, all registration and
filing fees, printing expenses, fees and disbursements of counsel and
independent public accountants for the Company, the reasonable fees and
disbursements of one counsel for the selling shareholders (which shall be
included in the Merger Expenses, as defined in the Merger Agreement), fees of
the National Association of Securities Dealers, Inc., transfer taxes and fees of
transfer agents and registrars, will be paid by the Company in connection with
the registration statement filed pursuant to Sections 2 and 3 hereof.

      5. Indemnification. The Company will indemnify and hold harmless each
seller of such Registerable Stock under the registration statement filed
pursuant to Sections 2 and 3 hereof, each partner, officer and director of each
such seller, and each other person, if any, who controls such seller within the
meaning of the Securities Act, against any losses, claims, damages or


                                       4


liabilities, joint or several, to which such seller, partner, officer, director
or controlling person may become subject under the Securities Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon (i) any untrue statement or alleged
untrue statement of any material fact contained in the registration statement
filed pursuant to Sections 2 and 3 hereof, any preliminary prospectus or final
prospectus contained therein, or any amendment or supplement thereof, (ii) the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, and
(iii) any violation or alleged violation by the Company of the Securities Act,
the Exchange Act, any state securities law or any rule or regulation promulgated
under any of the same in connection with the offering covered by such
registration statement, and the Company will reimburse each such seller,
partner, officer and director and each such controlling person for any legal or
other expenses reasonably incurred by them in connection with investigating or
defending any such loss, claim, damage, liability or action; provided, however,
that the Company will not be liable in any such case if and to the extent that
any such loss, claim, damage or liability arises out of or is based upon an
untrue statement or alleged untrue statement or omission or alleged omission so
made in reliance upon and in conformity with information furnished by such
seller or any of its partners, officers, directors or such controlling person in
writing specifically for use in such registration statement or prospectus.

      Each seller of such Registerable Stock under the registration statement
filed pursuant to Sections 2 and 3 hereof, severally and not jointly, will
indemnify and hold harmless the Company and each person, if any, who controls
the Company within the meaning of the Securities Act, each officer of the
Company who signs the registration statement, each director of the Company, and
each person who controls any of the foregoing within the meaning of the
Securities Act, against all losses, claims, damages or liabilities, joint or
several, to which the Company or such officer or director or controlling person
may become subject under the Securities Act or otherwise, insofar as such
losses, claims, damages or liabilities (or actions in respect thereof) arise out
of or are based upon (i) any untrue statement or alleged untrue statement of any
material fact contained in the registration statement filed pursuant to Sections
2 and 3 hereof, any preliminary prospectus or final prospectus contained
therein, or any amendment or supplement thereof, (ii) the omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, or (iii) any violation
or alleged violation by the Company of the Securities Act, the Exchange Act, any
state securities law or any rule or regulation promulgated under any of the same
in connection with the offering covered by such registration statement, and each


                                       5


such seller will reimburse the Company and each such officer, director and
controlling person for any legal or other expenses reasonably incurred by them
in connection with investigating or defending any such loss, claim, damage,
liability or action; provided, however, that such seller will be liable
hereunder in any such case if and only to the extent that any such loss, claim,
damage or liability arises out of or is based upon an untrue statement or
alleged untrue statement or omission or alleged omission made in reliance upon
and in conformity with information furnished in writing to the Company by such
seller specifically for use in such registration statement or prospectus.
Notwithstanding the foregoing, (i) no seller shall be liable for payments of
amounts paid in settlement of any loss, claim, damage, liability or action if
such settlement is effected without the consent of such seller (which consent
shall not be unreasonably withheld), and (ii) in no event shall the liability of
any seller of Registerable Stock under this Section 5 in connection with any
registration exceed the proceeds received by such seller from the sale of shares
of Registerable Stock in such registration.

      Promptly after receipt by an indemnified party hereunder of notice of the
commencement of any action, such indemnified party shall, if a claim in respect
thereof is to be made against the indemnifying party hereunder, notify the
indemnifying party in writing thereof, but the omission so to notify the
indemnifying party shall not relieve it from any liability which it may have to
any indemnified party other than under this Section 5. In case any such action
shall be brought against any indemnified party and it shall notify the
indemnifying party of the commencement thereof, the indemnifying party, shall be
entitled to participate in and, to the extent it shall wish, to assume and
undertake the defense thereof with counsel satisfactory to such indemnified
party, and, after notice from the indemnifying party to such indemnified party
of its election so to assume and undertake the defense thereof, the indemnifying
party, if it shall actually undertake the defense thereof, shall not be liable
to such indemnified party under this Section 5 for any legal expenses
subsequently incurred by such indemnified party in connection with the defense
thereof other than reasonable costs of investigation and of liaison with counsel
so selected; provided, however, that, if the defendants in any such action
include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be reasonable
defenses available to it which are different from or additional to those
available to the indemnifying party, or if the interests of the indemnified
party reasonably may be deemed to conflict with the interests of the
indemnifying party, the indemnified party shall have the right to select a
separate counsel and to assume such legal defenses and otherwise to participate
in the defense of such action, with the expenses and fees of such separate
counsel and other expenses related to such participation to be reimbursed by the
indemnifying party as 


                                       6


incurred.

      Notwithstanding the foregoing, any indemnified party shall have the right
to retain its own counsel in any such action, but the fees and disbursements of
such counsel shall be at the expense of such indemnified party unless (i) the
indemnifying party shall have failed to retain counsel for the indemnified
person as aforesaid or shall have failed to defend such action in accordance
with preceding paragraph or (ii) the indemnifying party and such indemnified
party shall have mutually agreed to the retention of such counsel. It is
understood that the indemnifying party shall not, in connection with any action
or related actions in the same jurisdiction, be liable for the fees and
disbursements of more than one separate firm qualified in such jurisdiction to
act as counsel for the indemnified party. The indemnifying party shall not be
liable for any settlement of any proceeding effected without its written
consent, but if settled with such consent or if there be a final judgment for
the plaintiff, the indemnifying party agrees to indemnify the indemnified party
from and against any loss or liability by reason of such settlement or judgment.

      If the indemnification provided for in the first two paragraphs of this
Section 5 is unavailable or insufficient to hold harmless an indemnified party
under such paragraphs in respect of any losses, claims, damages or liabilities
or actions in respect thereof referred to therein, then each indemnifying party
shall in lieu of indemnifying such indemnified party contribute to the amount
paid or payable by such indemnified party as a result of such losses, claims,
damages, liabilities or actions in such proportion as appropriate to reflect the
relative fault of the Company, on the one hand, and the sellers of such
Registerable Stock, on the other, in connection with the statements or omissions
which resulted in such losses, claims, damages, liabilities or actions as well
as any other relevant equitable considerations, including the failure to give
any notice under the third paragraph of this Section 5. The relative fault shall
be determined by reference to, among other things, whether the untrue or alleged
untrue statement of a material fact relates to information supplied by the
Company, on the one hand, or the sellers of such Registerable Stock, on the
other, and to the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission. The Company and
each of you agree that it would not be just and equitable if contributions
pursuant to this paragraph were determined by pro rata allocation (even if all
of the sellers of such Registerable Stock were treated as one entity for such
purpose) or by any other method of allocation which did not take account of the
equitable considerations referred to above in this paragraph. The amount paid or
payable by an indemnified party as a result of the losses, claims, damages,
liabilities or action in respect thereof, referred to above in this paragraph,
shall be deemed to include any legal or 


                                       7


other expenses reasonably incurred by such indemnified party in connection with
investigating or defending any such action or claim. Notwithstanding the
provisions of this paragraph, the sellers of such Registerable Stock shall not
be required to contribute any amount in excess of the amount, if any, by which
the total price at which the Common Stock sold by each of them was offered to
the public exceeds the amount of any damages which they would have otherwise
been required to pay by reason of such untrue or alleged untrue statement or
omission. No person guilty of fraudulent misrepresentations (within the meaning
of Section 11(f) of the Securities Act), shall be entitled to contribution from
any person who is not guilty of such fraudulent misrepresentation.

      6. Current Public Information. The Company agrees with you as follows:

            (a) The Company shall use its best efforts to make and keep public
      information available, as those terms are understood and defined in Rule
      144 under the Securities Act, at all times from and after the date hereof.

            (b) The Company shall use its best efforts to file with the
      Commission in a timely manner all reports and other documents as the
      Commission may prescribe under Section 13(a) or 15(d) of the Exchange Act.

            (c) The Company shall furnish to each holder of Registerable Stock
      forthwith upon request, (i) a copy of the most recent annual or quarterly
      report of the Company, and (ii) such other reports and documents so filed
      as a holder may reasonably request to avail itself of any rule or
      regulation of the Commission allowing a holder of Registerable Stock to
      sell any such securities without registration.

      7. Effectiveness of this Agreement. This Agreement shall become effective
at the Effective Time. If the Effective Time shall not occur, this Agreement
shall be of no force and effect.

      8. Miscellaneous.

            (a) All covenants and agreements contained in this Agreement by or
on behalf of any of the parties hereto shall bind and inure to the benefit of
the respective successors and assigns of the parties hereto whether so expressed
or not, provided, however, that the obligations of the Company hereunder shall
inure only to the benefit of you and a person who shall become a holder of
Registerable Stock by will or the laws of descent and distribution, and the term
"Registerable Stock" as used herein


                                       8


shall be limited to Registerable Stock held by you or any such person.

            (b) All notices, requests, consents and other communications
hereunder shall be in writing and shall be mailed by first class registered
mail, postage prepaid, addressed as follows:

            if to the Company, to it at Overlook at Great Notch, 150 Clove Road,
      Little Falls, New Jersey 07424, Attention: Chairman and Chief Executive
      Officer;

      if to any holder of Registerable Stock, at its address as set forth in
      Annex I hereto;

            if to any subsequent holder of Registerable Stock pursuant to
      Section 10(a) hereof to it at such address as may have been furnished to
      the Company in writing by such holder;

      or, in any case, at such other address or addresses as shall have been
      furnished in writing to the Company (in the case of a holder of
      Registerable Stock or to such holders of Registerable Stock (in the case
      of the Company).

            (c) This Agreement shall be governed by and construed in accordance
with the laws of the State of Delaware.

            (d) This Agreement constitutes the entire agreement of the parties
with respect to the subject matter hereof and may not be modified or amended
except in writing signed by the holders of not less than a majority of the
Registerable Stock.

            (e) This Agreement may be executed in two or more counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

      Please indicate your acceptance of the foregoing by signing and returning
the enclosed counterpart of this letter, whereupon this letter (herein sometimes
called "this Agreement") shall be a binding agreement between the Company and
you.


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                                                   Very truly yours,

                                                   THE BISYS GROUP, INC.


                                                   By: /s/ Lynn J. Mangum
                                                       -------------------------
                                                       Name: Lynn J. Mangum
                                                       Title: Chairman and Chief
                                                              Executive Officer

AGREED TO AND ACCEPTED
as of the date first
above written:


/s/ Peter C. Cowie
- ----------------------------------
Peter C. Cowie


/s/ Wendy B. Cowie
- ----------------------------------
Wendy B. Cowie


/s/ Harris S. Berlack, by Diane
L. Cooper, Attorney-in-Fact
- ----------------------------------
Harris S. Berlack

TECHNOLOGY LEADERS II L.P.


By: /s/ Jean C. Tempel
    ------------------------------
    Name: Jean C. Tempel
    Title: Special Limited Partner

TECHNOLOGY LEADERS II OFFSHORE C.V.


By: /s/ Jean C. Tempel
    ------------------------------
    Name: Jean C. Tempel
    Title: Special Limited Partner

ONE LIBERTY FUND III, L.P.


By: /s/ Stephen J. Ricci
    ------------------------------
    Name: Stephen J. Ricci
    Title: General Partner

                       [signatures continued on next page]


                                       10


                   [signatures continued from preceding page]

GILDE INTERNATIONAL FUND, B.V.


By: /s/ Stephen J. Ricci
    ------------------------------
    Name: Stephen J. Ricci
    Title: Attorney-in-Fact


/s/ Jean Tempel
- ----------------------------------
Jean Tempel


/s/ John Owens
- ----------------------------------
John Owens


/s/ Scott Wilson
- ----------------------------------
Scott Wilson

MICHAEL BROWN and JOHN THOMAS
BERLACK, or their successors,
as TRUSTEES for the HARRIS S.
BERLACK CHILDREN'S TRUST


By: /s/ John T. Berlack
    ------------------------------
    John T. Berlack, Trustee


By: /s/ Michael Brown
    ------------------------------
    Michael Brown, Trustee

FREDERICK H. COWIE, or his
successor, as TRUSTEE of the
COWIE CHILDREN'__S TRUST


By: /s/ Frederick H. Cowie
    ------------------------------
    Frederick H. Cowie, Trustee

                       [signatures continued on next page]


                                       11


                   [signatures continued from preceding page]


- ----------------------------------
Keith Bengston


- --------------------------------
Seth Cohen


/s/ Lisa Lincoln
- --------------------------------
Lisa Lincoln


/s/ Seth Nichols
- --------------------------------
Seth Nichols


/s/ Michael Reagan
- --------------------------------
Michael Reagan


/s/ Semmes Walsh
- --------------------------------
Semmes Walsh


/s/ John Whitlock
- --------------------------------
John Whitlock


/s/ James M. Marcella
- --------------------------------
James M. Marcella

Silicon Valley Bank


By:
   -----------------------------
   Name:
   Title:


                                       12


                                                                      SCHEDULE I

                                                              Number of Shares
Name and Address                                              of Common Stock
- ----------------                                              ----------------

Peter C. Cowie                                                    248,407
49 Salem Street
Andover, MA 01801

Wendy B. Cowie                                                      8,031
49 Salem Street
Andover, MA 01810

Frederick H. Cowie, or his Successor,                               6,884
as Trustee of the Cowie Children's Trust
49 Salem Street
Andover, MA 01810

Harris S. Berlack                                                 102,139
4 King Philip Road
Sudbury, MA 01776

Michael Brown and John Thomas Berlack,                              9,179
or their Successors, as Trustees of the
Harris S. Berlack Children's Trust
c/o Michael Brown
Brown & Brown
9 Canal Street
Boston, MA 02108

Technology Leaders II L.P.                                         70,802
Ten Post Office Square, Suite 1325
Boston, MA 02109

Technology Leaders II (Offshore) C.V.                              56,243
Ten Post Office Square, Suite 1325
Boston, MA 02109

One Liberty Fund III, L.P.                                         66,320
One Liberty Square
Boston, MA 02109

Gilde International Fund, B.V.                                        669
One Liberty Square
Boston, MA 02109

Jean Tempel                                                         9,240
c/o TL Ventures
Ten Post Office Square
Suite 1325
Boston, MA 02109

John Owens                                                          2,309
181 Hunt Valley
Berwyn, PA 19312

Scott Wilson                                                        2,309
c/o Shields & Company, Inc.
150 Federal Street
Boston, MA 02110


                                                              Number of Shares
Name and Address                                              of Common Stock
- ----------------                                              ----------------

Keith Bengston                                                         89
1455 Shawsheen Street
Tewksbury, MA 01876

Seth Cohen                                                             29
113 Seawall Street-Apt. 2
Brookline, MA 02146

Lisa Lincoln                                                          663
382 Stone Street
Walpole, MA 02081

Seth Nichols                                                        1,203
48 South Street
Medfield, MA 02052

Michael Regan                                                       1,106
3150 Iris Avenue, #10
Boulder, CO 80301

Semmes Walsh                                                        1,137
38 Atwood Street
Wellesley, MA 02181

John Whitlock                                                       1,276
P.O. Box 521
Colchester, VT 05446

James M. Marcella                                                     114
223 Hanover Street
Boston, MA 02113

Silicon Valley Bank                                                   796
3003 Tasman Drive
NC 821
Santa Clara, CA 95054
Attn: David Jacques