<PAGE>

                                                                  EXHIBIT 10.49

                           LOAN MODIFICATION AGREEMENT

      This Loan Modification Agreement (this "Loan Modification Agreement")
dated as of January 15, 2004, and effective as of January 2, 2003, by and
between SILICON VALLEY BANK, a California-chartered bank, with its principal
place of business at 3003 Tasman Drive, Santa Clara, California 95054 and with a
loan production office located at One Newton Executive Park, Suite 200, 2221
Washington Street, Newton, Massachusetts 02462, doing business under the name
"Silicon Valley East" ("Bank") and MOLDFLOW CORPORATION, a Delaware corporation
with its chief executive office located at 430 Boston Post Road, Wayland,
Massachusetts 01778 ("Borrower").

1. DESCRIPTION OF EXISTING INDEBTEDNESS AND OBLIGATIONS. Among other
indebtedness and obligations which may be owing by Borrower to Bank, Borrower is
indebted to Bank pursuant to a loan arrangement dated as of November 13, 2001,
evidenced by, among other documents, a certain Loan Agreement dated as of
November 13, 2001, between Borrower and Bank, as amended by certain Loan
Modification Agreements dated June 11, 2001, June 26, 2001, December 6, 2002,
and June 25, 2003 (as amended, the "Loan Agreement"). Capitalized terms used but
not otherwise defined herein shall have the same meaning as in the Loan
Agreement.

Hereinafter, the Loan Agreement, together with all other documents evidencing
the Obligations shall be referred to as the "Existing Loan Documents".

2. DESCRIPTION OF CHANGE IN TERMS.

      A.    Modifications to Loan Agreement.

            1.    The Loan Agreement shall be amended by deleting the following
                  provision appearing as 2.1.1 (a) thereof:

                        "2.1.1 REVOLVING ADVANCES.

                              (a) Bank shall make Advances not exceeding (i) the
                        Committed Line or the Borrowing Base, whichever is less,
                        minus (ii) the amount of all outstanding Letters of
                        Credit (including drawn but unreimbursed Letters of
                        Credit), minus (iii) the FX Reserve, and minus (iv) the
                        aggregate outstanding Advances hereunder (including any
                        Cash Management Services). Amounts borrowed under this
                        Section may be repaid and reborrowed during the term of
                        this Agreement."

                  and inserting in lieu thereof the following:

                        "2.1.1 REVOLVING ADVANCES.

                              (a) Bank shall make Advances not exceeding: (i)
                        the lessor of: (A) the Committed Line or, (B) the
                        aggregate of (1) the Borrowing Base, plus (2) Permitted
                        Overadvance, minus (ii) the amount of all outstanding
                        Letters of Credit (including drawn but unreimbursed
                        Letters of Credit), minus (iii) the FX Reserve, and
                        minus (iv) the aggregate outstanding Advances hereunder
                        (including any Cash Management Services). Amounts
                        borrowed under this Section may be repaid and reborrowed
                        during the term of this Agreement."
<PAGE>
            2.    The Loan Agreement shall be amended by deleting the following
                  provision appearing as Section 2.1.2(a) thereof:

                        "2.1.2 LETTERS OF CREDIT SUBLIMIT.

                              (a) Bank shall issue or have issued Letters of
                        Credit for Borrower's account not exceeding (i) the
                        lesser of the Committed Line or the Borrowing Base,
                        minus (ii) the outstanding principal balance of any
                        Advances (including any Cash Management Services), minus
                        (iii) the amount of all Letters of Credit (including
                        drawn but unreimbursed Letters of Credit), plus an
                        amount equal to any Letter of Credit Reserves. The face
                        amount of outstanding Letters of Credit (including drawn
                        but unreimbursed Letters of Credit and any Letter of
                        Credit Reserve) may not exceed Five Million Dollars
                        ($5,000,000.00). Borrower's Letter of Credit
                        reimbursement obligation shall be secured by cash on
                        terms acceptable to Bank on and after (i) the Maturity
                        Date if the term of this Agreement is not extended by
                        Bank, or (ii) the occurrence of an Event of Default
                        hereunder. All Letters of Credit shall be, in form and
                        substance, acceptable to Bank in its sole discretion and
                        shall be subject to the terms and conditions of Bank's
                        form of standard Application and Letter of Credit
                        Agreement. Borrower agrees to execute any further
                        documentation in connection with the Letters of Credit
                        as Bank may reasonably request"

                  and inserting in lieu thereof the following:

                        "2.1.2 LETTERS OF CREDIT SUBLIMIT.

                              (a) Bank shall issue or have issued Letters of
                        Credit for Borrower's account not exceeding the lesser
                        of: (i) (A) the Committed Line or, (B) the aggregate of
                        (1) the Borrowing Base, plus (2) Permitted Overadvance,
                        minus (ii) the outstanding principal balance of any
                        Advances (including any Cash Management Services), minus
                        (iii) the amount of all Letters of Credit (including
                        drawn but unreimbursed Letters of Credit), plus an
                        amount equal to any Letter of Credit Reserves. The face
                        amount of outstanding Letters of Credit (including drawn
                        but unreimbursed Letters of Credit and any Letter of
                        Credit Reserve) may not exceed Five Million Dollars
                        ($5,000,000.00 ). Borrower's Letter of Credit
                        reimbursement obligation shall be secured by cash on
                        terms acceptable to Bank on and after (i) the Maturity
                        Date if the term of this Agreement is not extended by
                        Bank, or (ii) the occurrence of an Event of Default
                        hereunder. All Letters of Credit shall be, in form and
                        substance, acceptable to Bank in its sole discretion and
                        shall be subject to the terms and conditions of Bank's
                        form of standard Application and Letter of Credit
                        Agreement. Borrower agrees to execute any further
                        documentation in connection with the Letters of Credit
                        as Bank may reasonably request."
<PAGE>
            3.    The Loan Agreement shall be amended by deleting the following
                  provision appearing as Section 2.2 thereof:

                        "2.2 OVERADVANCES. If Borrower's Obligations under
                  Section 2.1.1, 2.1.2, 2.1.3, and 2.1.4 exceed the lesser of
                  either (i) the Committed Line or (ii) the Borrowing Base,
                  Borrower must immediately pay in cash to Bank the excess."

                  and inserting in lieu thereof the following:

                        "2.2 OVERADVANCES. If Borrower's Obligations under
                  Section 2.1.1, 2.1.2, 2.1.3, and 2.1.4 exceed the lesser of:
                  (i) the Committed Line or (ii) the aggregate of (A) the
                  Borrowing Base, plus (B) the Permitted Overadvance, Borrower
                  must immediately pay in cash to Bank the excess. By way of
                  example, in the event the Borrower has Advances of One Million
                  One Hundred Thousand Dollars ($1,100,000.00), the Borrowing
                  Base must be equal to or greater than One Hundred Thousand
                  Dollars ($100,000.00)."

            4.    The Loan Agreement is amended by deleting the following
                  provisions appearing as Section 5.2 (a) and (b) thereof:

                        "5.2 FINANCIAL STATEMENTS, REPORTS, CERTIFICATES.

                              (a) Borrower shall deliver to Bank: (i) no later
                        than thirty (30) days after the last day of each
                        quarter, and if there are Advances outstanding then no
                        later than thirty (30) days after the last day of each
                        month, a company prepared consolidated balance sheet and
                        income statement covering Borrower's consolidated
                        operations during the period certified by a Responsible
                        Officer and in a form acceptable to Bank; (ii) as soon
                        as available, but no later than one hundred and twenty
                        (120) days after the last day of Borrower's fiscal year,
                        audited consolidated financial statements prepared under
                        GAAP, consistently applied, together with an unqualified
                        opinion on the financial statements from an independent
                        certified public accounting firm reasonably acceptable
                        to Bank; (iii) within five (5) days of filing, copies of
                        all statements, reports and notices made available to
                        Borrower's security holders and all reports on Form
                        10-K, 10-Q and 8-K filed with the Securities and
                        Exchange Commission; (iv) a prompt report of any legal
                        actions pending or threatened against Borrower or any
                        Subsidiary that could result in damages or costs to
                        Borrower or any Subsidiary of Five Hundred Thousand
                        Dollars ($500,000.00) or more, in the aggregate; and (v)
                        or other financial information reasonably requested by
                        Bank.

                              (b) Borrower shall deliver to Bank a Borrowing
                        Base Certificate signed by a Responsible Officer in the
                        form of EXHIBIT B, with aged listings of accounts
                        receivable (by invoice date): (i) within twenty-five
                        (25) days of the last day of each month in which
                        Advances were outstanding, and (ii) within twenty-five
                        (25) days of the last day of each quarter.
<PAGE>
                  and inserting in lieu thereof the following:

                        "5.2 FINANCIAL STATEMENTS, REPORTS, CERTIFICATES.

                              (a) Borrower shall deliver to Bank: (i) no later
                        than thirty (30) days after the last day of each
                        quarter, and if there are Advances outstanding then no
                        later than thirty (30) days after the last day of each
                        month, a company prepared consolidated balance sheet and
                        income statement covering Borrower's consolidated
                        operations during the period certified by a Responsible
                        Officer and in a form acceptable to Bank; (ii) as soon
                        as available, but no later than one hundred and twenty
                        (120) days after the last day of Borrower's fiscal year,
                        audited consolidated financial statements prepared under
                        GAAP, consistently applied, together with an unqualified
                        opinion on the financial statements from an independent
                        certified public accounting firm reasonably acceptable
                        to Bank; (iii) a prompt report of any legal actions
                        pending or threatened against Borrower or any Subsidiary
                        that could result in damages or costs to Borrower or any
                        Subsidiary of Five Hundred Thousand Dollars
                        ($500,000.00) or more, in the aggregate; and (iv) or
                        other financial information reasonably requested by
                        Bank.

                              (b) Borrower shall deliver to Bank a Borrowing
                        Base Certificate signed by a Responsible Officer in the
                        form of Exhibit C, with aged listing of accounts
                        receivable (by invoice date): (i) within twenty-five
                        (25) days of the last day of each month in which
                        Advances were outstanding, and (ii) within forty-five
                        (45) days of the last day of each quarter in which
                        Credit Extensions (other than Advances) were
                        outstanding."

            5.    The Loan Agreement shall be amended by deleting the following,
                  appearing as Section 5.6 thereof, in its entirety:

                              "5.6 PRIMARY ACCOUNTS. Borrower shall maintain its
                        primary operating accounts with the Bank. The
                        outstanding balance of Borrower's investment/securities
                        account, held at the Bank, shall as of the date of this
                        Agreement equal Ten Million Dollars ($10,000,000.00) in
                        cash and marketable securities. In addition to the
                        foregoing requirement, in the event that Bank offers
                        competitive rates of return, Borrower shall use its best
                        efforts to deposit, beginning with the date which is six
                        (6) months after the Closing Date, an additional
                        aggregate amount of Five Million Dollars ($5,000,000.00)
                        in investment and securities accounts with Bank. Such
                        amounts are initial balances only and Borrower and Bank
                        agree that such amounts may decrease from time to time
                        on changes in market value or transfers of cash in
                        accordance with this Agreement."

                  and inserting in lieu thereof the following:

                              "5.6 PRIMARY ACCOUNTS. Borrower shall maintain its
                        primary operating accounts with the Bank. The
                        outstanding balance of Borrower's investment/securities
                        account, held at the Bank, shall as of the date of this
                        Agreement, equal Ten Million Dollars ($10,000,000.00)
                        in cash and marketable securities. In addition to the
                        foregoing requirement, in the event that Bank offers
                        competitive rates of return, Borrower shall use its
                        reasonable best efforts to deposit additional funds in
                        investment and securities accounts with Bank. Such
                        amounts are initial balances only and Borrower and Bank
                        agree that such amounts may decrease from time to time
                        on changes in market value or transfers of cash in
                        accordance with this Agreement."
<PAGE>
            6.    The Loan Agreement shall be amended by deleting the following,
                  appearing as Section 6.3 thereof, in its entirety:

                        "6.3 MERGERS OR ACQUISITIONS. Merge or consolidate, or
                        permit any of its Subsidiaries to merge or consolidate,
                        with any other Person, or acquire, or permit any of its
                        Subsidiaries to acquire, all or substantially all of the
                        capital stock or property of another Person other than
                        (i) mergers, consolidations, capital contributions,
                        acquisitions, or other like transactions between Parent
                        and any Subsidiary or between Subsidiaries, (ii)
                        acquisitions by Borrower of all or substantially all of
                        the capital stock or property of another Person (each
                        instance of the above defined as a "Transaction");
                        provided, however, that (A) each Transaction does not
                        decrease Borrower's cash and cash equivalents by more
                        than Seven Million Five Hundred Thousand Dollars
                        ($7,500,000.00); (B) the aggregate Transactions in any
                        fiscal year do not decrease Borrower's cash and cash
                        equivalents by more than Fifteen Million Dollars
                        ($15,000,000.00); (C) each Transaction will not result,
                        whether solely as a result of the passage of time, or
                        otherwise, in the occurrence of an Event of Default; and
                        (D) Borrower is the surviving entity."

                  and inserting in lieu thereof the following:

                        "6.3 MERGERS OR ACQUISITIONS. Merge or consolidate, or
                        permit any of its Subsidiaries to merge or consolidate,
                        with any other Person, or acquire, or permit any of its
                        Subsidiaries to acquire, all or substantially all of the
                        capital stock or property of another Person other than
                        (i) mergers, consolidations, capital contributions,
                        acquisitions, or other like transactions between Parent
                        and any Subsidiary or between Subsidiaries, (ii)
                        acquisitions by Borrower of all or substantially all of
                        the capital stock or property of another Person (each
                        instance of the above defined as a "Transaction");
                        provided, however, that (A) each Transaction does not
                        decrease Borrower's cash and cash equivalents by more
                        than Fourteen Million Dollars ($14,000,000.00); (B) the
                        aggregate Transactions in any fiscal year do not
                        decrease Borrower's cash and cash equivalents by more
                        than Twenty Million Dollars ($20,000,000.00); (C) each
                        Transaction will not result, whether solely as a result
                        of the passage of time, or otherwise, in the occurrence
                        of an Event of Default; and (D) Borrower is the
                        surviving entity."

            7.    The Loan Agreement shall be amended by deleting the following
                  definition appearing in Section 13.1 thereof:

                        ""Maturity Date" means January 3, 2003."

                  and inserting in lieu thereof the following:

                        ""Maturity Date" means December 2, 2004."

            8.    The Loan Agreement shall be amended by inserting the
                  following definition to appear alphabetically in Section 13.1
                  thereof:

                        ""Permitted Overadvance" is an Advance or Advances under
                        the Committed Line of up to One Million Dollars
                        ($1,000,000.00).
<PAGE>
            9.    The Compliance Certificate appearing as EXHIBIT C to the Loan
                  Agreement is hereby replaced with the Compliance Certificate
                  attached as EXHIBIT A hereto.

3. FEES. Borrower shall pay to Bank a modification fee equal to Twelve Thousand
Five Hundred Dollars ($12,500.00), which fee shall be due on the date hereof
and shall be deemed fully earned as of the date hereof. The Borrower shall also
reimburse Bank for all legal fees and expenses incurred in connection with this
amendment to the Existing Loan Documents.

4. CONSISTENT CHANGES. The Existing Loan Documents are hereby amended wherever
necessary to reflect the changes described above.

5. RATIFICATION OF LOAN DOCUMENTS. Borrower hereby ratifies, confirms, and
reaffirms all terms and conditions of the Existing Loan Documents, and confirms
that the indebtedness includes, without limitation, the Obligations.

6. NO DEFENSES OF BORROWER. Borrower hereby acknowledges and agrees that
Borrower has no offsets, defenses, claims, or counterclaims against Bank with
respect to the Obligations, or otherwise, and that if Borrower now has, or ever
did have, any offsets, defenses, claims, or counterclaims against Bank, whether
known or unknown, at law or in equity, all of them are hereby expressly WAIVED
and Borrower hereby RELEASES Bank from any liability thereunder.

7. CONTINUING VALIDITY. Borrower understands and agrees that in modifying the
existing Obligations, Bank is relying upon Borrower's representations,
warranties, and agreements, as set forth in the Existing Loan Documents. Except
as expressly modified pursuant to this Loan Modification Agreement, the terms of
the Existing Loan Documents remain unchanged and in full force and effect.
Bank's agreement to modifications to the existing Obligations pursuant to this
Loan Modification Agreement in no way shall obligate Bank to make any future
modifications to the Obligations. Nothing in this Loan Modification Agreement
shall constitute a satisfaction of the Obligations. It is the intention of Bank
and Borrower to retain as liable parties all makers of Existing Loan Documents,
unless the party is expressly released by Bank in writing. No maker will be
released by virtue of this Loan Modification Agreement.

8. COUNTERSIGNATURE. This Loan Modification Agreement shall become effective
only when it shall have been executed by Borrower and Bank (provided, however,
in no event shall this Loan Modification Agreement become effective until signed
by an officer of Bank in California).

            [The remainder of this page is intentionally left blank]
<PAGE>
      This Loan Modification Agreement is executed as a sealed instrument under
the laws of the Commonwealth of Massachusetts as of the date first written
above.

BORROWER:                                 BANK:

MOLDFLOW CORPORATION                      SILICON VALLEY BANK, doing business as
                                          SILICON VALLEY EAST

By: /s/ Suzanne E. MacCormack             By: /s/ Mark Gallagher
    ________________________________          __________________________________

Name:   Suzanne E. MacCormack             Name:   Mark Gallagher
    _______________________________           _________________________________

Title:  Executive Vice President          Title:
      ______________________________            ________________________________


                                          SILICON VALLEY BANK

                                          By:___________________________________

                                          Name:_________________________________

                                          Title:________________________________
                                                 (signed in Santa Clara County,
                                                        California)
<PAGE>
                                    EXHIBIT A

                             COMPLIANCE CERTIFICATE

TO: SILICON VALLEY BANK

FROM: MOLDFLOW CORPORATION

      The undersigned authorized officer of Moldflow Corporation certifies that
under the terms and conditions of the Loan Agreement between Borrower and Bank
(the "Agreement"), (i) Borrower is in complete compliance for the period ending
_____ _____ _____ with all required covenants except as noted below and (ii) all
representations and warranties in the Agreement are true and correct in all
material respects on this date. Attached are the required documents supporting
the certification. The Officer certifies that these are prepared in accordance
with Generally Accepted Accounting Principles (GAAP) consistently applied from
one period to the next except as explained in an accompanying letter or
footnotes. The Officer acknowledges that no borrowings may be requested at any
time or date of determination that Borrower is not in compliance with any of the
terms of the Agreement, and that compliance is determined not just at the date
this certificate is delivered.

      PLEASE INDICATE COMPLIANCE STATUS BY CIRCLING YES/NO UNDER "COMPLIES"
COLUMN.

<TABLE>
<CAPTION>
        REPORTING COVENANT                            REQUIRED                                      COMPLIES
        ------------------                            --------                                      --------
<S>                                       <C>                                                   <C>           <C>
Interim financial statements with CC      Quarterly within 30 days                              Yes           No
                                          Monthly if Advances outstanding

Annual (CPA Audited)                      FYE within 120 days                                   Yes           No

BBC with A/R Agings                       Monthly within 25 in which Advances                   Yes           No
                                          outstanding Quarterly within 45 days
                                          in which Credit Extension (other than
                                          Advances) outstanding
</TABLE>

<TABLE>
<CAPTION>
      FINANCIAL COVENANT                        REQUIRED                        ACTUAL                 COMPLIES
      ------------------                        --------                        ------                 --------
<S>                                       <C>                              <C>                        <C>
Maintain on a Quarterly Basis:

Minimum Liquidity                         $30,000,000.00                   $ ____________             Yes       No


Maximum Net Loss: ($* )                   ($____________)                  $ ____________             Yes       No
</TABLE>

*(i)  $500,000.00 for the Borrower's fiscal quarter ending 12/27/03 and for
      each quarter thereafter.

COMMENTS REGARDING EXCEPTIONS:  See Attached.

Sincerely,

_____________________________
SIGNATURE

_____________________________
TITLE

_____________________________
DATE

                                  BANK USE ONLY

Received by: ____________________________
                  AUTHORIZED SIGNER

Date: ___________________________________


Verified: _______________________________
                 AUTHORIZED SIGNER

Date: ___________________________________