Document:

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                                                                     EXHIBIT 4.9

             AMENDMENT NO. 2 TO PREFERRED SHARES RIGHTS AGREEMENT
                         BETWEEN CATALYTICA, INC. AND
                   CHASEMELLON SHAREHOLDER SERVICES, L.L.C.

      This Amendment No. 2 to the Preferred Shares Rights Agreement, dated as of
October 23, 1996, as amended by Amendment No. 1, dated as of July 28, 1997 (the
"Rights Agreement"), between Catalytica, Inc. (the "Company") and ChaseMellon
Shareholder Services, L.L.C., as Rights Agent (the "Rights Agent"), is dated as
of August 2, 2000.

      WHEREAS, the Company expects to enter into an Agreement and Plan of
Merger, by and among Synotex, Inc., Synotex Acquisition Corporation, and the
Company, in substantially the form as approved by the Board of Directors of the
Company on August 2, 2000 (the "Merger Agreement");

      WHEREAS, as an inducement and a condition to entering into the Merger
Agreement, Morgan Stanley Capital Partners III, L.P., Morgan Stanley Capital
Investors, L.P., MSCP III 892 Investors, L.P., James A. Cusumano, Ricardo B.
Levy, Synotex, Inc. and the Company will enter into a Voting Agreement (the
"Voting Agreement"), providing for, among other things, each Stockholder Party
(as defined therein) agreeing to vote for the transactions contemplated by the
Merger Agreement;

      WHEREAS, Section 27 of the Rights Agreement permits the Company to amend
the Rights Agreement in any respect without approval of the holders of rights
prior to the occurrence of a Triggering Event (as therein defined);

      WHEREAS, a Triggering Event has not occurred;

      WHEREAS, the Board of Directors of the Company authorized and approved
this Amendment at the Special Meeting of the Board of Directors of the Company
on August 2, 2000; and

      WHEREAS, the Company deems it desirable and in the best interests of the
Company to amend the Rights Agreement as set forth herein;

      NOW, THEREFORE, in consideration of the mutual promises and covenants
contained herein and in the Rights Agreement, the parties hereto hereby agree as
follows:

      1.     NEW SECTION.  Section 36 is hereby added to the Rights Agreement.
Such new section shall read in its entirety as follows:

      "36.   Exclusion of Certain Transactions with Synotex, Inc.

      Notwithstanding anything contained in this Agreement to the contrary:
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     (a)  This Section 36 is included in this Agreement in connection with the
          Agreement and Plan of Merger, by and among Synotex, Inc., Synotex
          Acquisition Corporation, and the Company, in substantially the form as
          approved by the Board of Directors of the Company on August 2, 2000
          (the "Merger Agreement"). In the event that the Merger Agreement is
          terminated prior to the Closing (as defined in the Merger Agreement),
          this Section 36 shall be of no further force and effect and shall be
          considered to be deleted from this Agreement. The Rights Agent shall
          incur no liability in assuming the effectiveness of this Section 36
          unless and until it has been notified by the Company that this Section
          36 is of no further force and effect.

     (b)  The execution and delivery of the Merger Agreement and that certain
          Voting Agreement by and among Morgan Stanley Capital Partners III,
          L.P., Morgan Stanley Capital Investors, L.P., MSCP III 892 Investors,
          L.P., James A. Cusumano, Ricardo B. Levy, Synotex, Inc. and the
          Company dated as of August 2, 2000 (the "Voting Agreement") and
          consummation of the transactions contemplated thereby shall in no
          event result in (i) Synotex, Inc. becoming an Acquiring Person, or
          (ii) a distribution of Rights pursuant to this Agreement, or (iii) the
          exercisability of, or any adjustment to, Rights under this Agreement,
          or (iv) any other defensive measures under this Agreement.

      3.     NO OTHER CHANGES.  Except as expressly amended hereby, the Rights
Agreement shall remain in full force and effect.

      4.     DIRECTION OF COMPANY.  Pursuant to Section 27 of the Rights
Agreement, the Company directs the Rights Agent to execute this Amendment.

      5.     COUNTERPARTS.  This Amendment may be executed in any number of
counterparts, and each of such counterparts shall for all purposes be deemed to
be an original, and all such counterparts shall together constitute one and the
same instrument.

                  [Remainder of page intentionally left blank]

                                      -2-
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      IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed as of the day and year first above written.

                           CATALYTICA, INC.

                           By:  /s/  Lawrence W. Briscoe
                                ---------------------------------------
                                Lawrence W. Briscoe
                                Vice President, Finance and Administration and
                                Chief Financial Officer

                           CHASEMELLON SHAREHOLDER SERVICES, L.L.C.,
                                as Rights Agent

                           By:  /s/  Asa Drew
                                ---------------------------------------
                                Asa Drew
                                Assistant Vice President

    [Signature Page to Amendment No. 2 to Preferred Shares Rights Agreement]

                                      -3-<PAGE>

                                                              Exhibit 10.01
                      AMENDMENT TO IRU CAPACITY AGREEMENT

This Amendment ("Amendment"), effective April 30, 1999 (the "Effective Date"),
amends the IRU Capacity Agreement ("Agreement") entered into as of December 19,
1998 between AT&T Corp. ("AT&T"), a New York corporation with offices at 295
North Maple Avenue, Basking Ridge, New Jersey 07920, and At Home Corporation,
("@Home"), a Delaware corporation with a principal place of business located at
425 Broadway, Redwood City, CA  94063, as follows:

                                   BACKGROUND

Pursuant to the Agreement, AT&T granted to @Home an indefeasible right to use
optical fibers and dedicated circuit capacity on the AT&T Network.

Pursuant to Section 3.1 of the Agreement, AT&T agreed to assist @Home's
transition to the AT&T Network, during the period from January 1, 1999 through
Acceptance of the Phase Two Services, by assuming @Home's rights and obligations
under the Sprint ATM Arrangement.

Also pursuant to Section 3.1 of the Agreement, in the event AT&T incurs charges
under the Sprint ATM Arrangement in excess of five million dollars, @Home agreed
to pay the amount of any such excess to AT&T as an Assumption Fee, except that
if AT&T does not deliver the Phase Two Capacity by the Phase Two Commitment
Date, the charges incurred under the Sprint ATM Arrangement from April 1, 1999
through the date on which AT&T delivers the Phase Two Capacity would not be
counted in calculating any Assumption Fee.

THEREFORE, the parties hereby amend the Agreement as follows:

                                   AMENDMENT

1.  In Section 3.1, sentence five (5), replace "five million dollars" with "nine
million dollars."

2.  In Section 5.1, after "ninety million dollars ($90,000,000) (the "IRU
Fee"), add "and four million dollars ($4,000,000) (the "Additional IRU Fee").

3.  In Exhibit I (Payment Terms), add at the end:  "Additional IRU Fee.  @Home
shall pay the Additional IRU Fee on July 1, 1999."

4.  Except as modified above, all other terms and conditions of the Agreement
remain in full force and effect.  Terms used and not defined herein will have
the meanings assigned to them in the Agreement.  In the event of any conflict
between the provisions of the Amendment and the Agreement, the provisions of
this Amendment shall govern.
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IN WITNESS WHEREOF, authorized representatives of the parties have executed this
Amendment as of the Effective Date.

AT&T CORP.                         AT HOME CORPORATION

By: /s/                            By:  /s/ David Pine
   ---------------------------        ---------------------------

Title: Pres. Wholesale Mkts.       Title: VP, General Counsel
      ------------------------           ------------------------

Date:  7/1/99                      Date:  6/28/99
     -------------------------          -------------------------<PAGE>

                                                                   Exhibit 10.02

               AMENDMENT NUMBER THREE TO IRU CAPACITY AGREEMENT

This Amendment Number Three ("Amendment"), effective as of the date signed by
both parties (the "Effective Date"), amends the IRU Capacity Agreement
("Agreement") entered into as of December 19, 1998 between AT&T Corp. ("AT&T"),
a New York corporation with offices at 295 North Maple Avenue, Basking Ridge,
New Jersey 07920, and At Home Corporation, ("@Home"), a Delaware corporation
with a principal place of business located at 425 Broadway, Redwood City, CA
94063, as previously amended, as follows:

1.  Under the terms of Section 6.2 of the Agreement, @Home has the right to
request an expansion of the @Home Backbone Network to include a new Route,
referred to in the Agreement as a Route Expansion.  @Home has exercised this
right with respect to the four Routes listed below, and the following Additional
Capacity is added to the Capacity provided under the Agreement:

<TABLE>
<CAPTION>
  No.    City A                 City Z              CLLI Code A      CLLI Code Z     Miles
<S>                          <C>                    <C>               <C>            <C>
   1   Anaheim, CA           Tucumcari, NM           ANHMCA01          TCMCNM02       1266.3
   2   Anaheim, CA           Las Vegas, NV           ANHMCA01          LSVGNV02       297.0
   3   Las Vegas, NV         Albuquerque, NM         LSVGNV02          ALBQNMMA       724.9
   4   Albuquerque, NM       Tucumcari, NM           ALBQNMMA          TCMCNM02       244.4
</TABLE>

2.  The Capacity to be provided on these new Routes initially consists of one
OC-48 on each Route (including network electronics and circuit electronics). As
provided in Section 6.1 of the Agreement, @Home may purchase from AT&T
additional network electronics and circuit electronics in order to increase the
Capacity on the Routes to the Market Equivalent Capacity.

3.  The IRU Fee associated with this Route Expansion is $4,835,200.  @Home shall
pay $483,520 to AT&T within ten days after the Effective Date, and $4,351,680
within ten days after the Acceptance Date with respect to the Route Expansion.

IN WITNESS WHEREOF, authorized representatives of the parties have executed this
Amendment as of the Effective Date.

AT&T CORP.                             AT HOME CORPORATION

By: /s/                                By:  /s/ Milo Medin
   ----------------------------            ----------------------------

Title: Senior Vice President           Title: CTO
      -------------------------              --------------------------

Date:  3/29/00                         Date:  2/28/00
     --------------------------             ---------------------------

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