<PAGE>
                                                                    EXHIBIT 4.18

                             FOR PRINCIPAL OFFICERS

                         EXECUTIVE EMPLOYMENT AGREEMENT


This Executive Employment Agreement ("Agreement") is entered into in Chennai
India on 20th February, 2002 between:

1.    Satyam Infoway Limited ("Sify") a company incorporated in India and having
      its principal office at Tidel Park 2nd floor, 4 Canal Bank road, Taramani,
      Chennai 600 113 India and

2.    Mr. T. R. Santhanakrishnan ("Executive") residing at A2 Alsa Brentwood, 38
      First Main Road, R. A. Puram, Chennai -- 600 028.

The operations of Sify and its affiliates are a complex matter requiring
direction and leadership in a variety of areas including strategic planning,
financial, regulatory, community relations and others. Executive is currently
employed as Sify's Chief Financial Officer. Considering the current status of
Sify's operation, Sify desires that the Executive should continue in the
employment of Sify and has requested the Executive to continue as its Chief
Financial Officer and the Executive has agreed to do so subject to the terms and
conditions contained herein .

Sify and the Executive agree as follows:

1.    Sify would continue to employ the Executive as its Chief Financial
      Officer. Executive agrees to continue such employment. The position is
      based in Chennai, India. This agreement shall be valid for an initial
      period of Three (3) years from 20.02.2002 till 20.02.2005.

2.    During the term of employment the Executive shall:

      a.   Observe and comply with the policies of Sify
      b.   Serve Sify faithfully, diligently and competently to the best of his
           ability.
      c.   Report to the Managing Director and CEO and the Board of Directors of
           Sify
      d.   Serve, without further compensation, as Director of one or more of
           Sify's affiliates as desired by Sify

3.    During the term of employment the Executive shall not, without prior
      written consent of Sify's Board of Directors:
      a.   Accept any other employment with a third party
      b.   Serve on the Board of Directors or any similar body of any other
           business entity
      c.   Engage directly or indirectly in any other business activity that
           competes with the business of Sify and its affiliates. (Affiliates
           mean and include businesses in which Sify has an equity or debt stake
           in excess of 5% of the capital of such business).

4.    During the term of employment the Executive shall be entitled to following
      "compensation and benefits" (all subject to deduction of tax as per
      applicable law):
      a.   "Base salary" as set out in Annexure A which includes Salary,
           allowances, benefits and perquisites or as amended with mutual
           consent from time to time
      b.   "Performance bonus" as set out in Annexure B which is a variable pay
           linked to performance or as amended with mutual consent from time to
           time
      c.   Vacation/leave as per Sify's policy for Employees
      d.   Reimbursement of business expenses incurred on Sify's behalf as per
           Sify's policy for business expenses incurred by Employees

5.    Executive acknowledges that because of his employment, he is in a
      confidential relationship with Sify and has access to confidential
      information and trade secrets of Sify. Confidential information or trade
      secrets include all information relating to customers, business
      strategies/plans, business investments, marketing plans/techniques,
      business operation methods/practices etc. Executive agrees that such
      confidential information or trade secrets shall not be disclosed by him to
      any third party except when mandated by law and shall not be used by him
      for any purpose except in the performance of his work for Sify.

6.    Executive agrees that all work of a copyrightable or patentable nature
      done in the course of work for Sify belong to Sify and undertakes to help
      in every way to get Sify's ownership of such copyrights/patents duly
      registered.


<PAGE>


7.    Sify agrees to indemnify the Executive, his executors, administrators or
      assigns for all Expenses (as defined) which the Executive incurs or
      is/becomes legally obligated to pay in connection with any Proceedings (as
      defined).

      "Expenses" shall include, without limitation, damages, judgments, fines,
      penalties, settlements and costs, attorney's fees/expenses, costs of
      attachment or similar bonds, investigations and any expenses of
      establishing a right to indemnification.

      "Proceeding" shall include any threatened, pending or completed claim,
      action, suit or proceeding, whether brought by or in the right of Sify or
      otherwise and whether of a civil, criminal, administrative or
      investigative nature, in which Executive may be or may have been involved
      as a party or otherwise
      a.   by reason of the Executive's employment in Sify or
      b.   by reason of the Executive, at Sify's request, being a director or
           officer of any company or
      c.   by reason of any actual or alleged error or misstatement or
           misleading statement made or suffered by Executive, or
      d.   by reason of any action taken by him or of any inaction on the
           Executive's part.

      Such an agreement by Sify to indemnify the Executive shall not apply
      a.   to any obligation by Executive to disgorge profits made from sale and
           purchase of securities pursuant to Securities Exchange regulations
           applicable where the securities of Sify are listed.
      b.   to any obligation of Executive arising from any willful act
           i.   that has resulted in personal financial gain to the Executive or
           ii.  that was done with a malicious intent or
           iii. of gross negligence by the Executive.

      Sify agrees to advance money to the Executive for Expenses to be incurred
      upon request by the Executive. Executive undertakes to render true and
      complete accounts of the expenses and to repay Sify any advance in excess
      of actual Expenses indemnifiable under this Agreement.

      Indemnification obligation shall not apply to any proceeding/action
      brought by the Executive without prior approval of Sify unless such an
      proceeding/action is to establish the right of the Executive under this
      Agreement.

      This clause applies with retrospective effect from the date Executive
      commenced his employment with Sify (even though that date is prior to this
      Agreement) and extends even after Executive ceases to be in the employment
      of Sify. This clause survives the expiry or earlier termination of this
      Agreement.

8.    This agreement (except clause 7 above) terminates on the expiry of the
      term of this agreement unless both parties agree to renew it six months
      before the expiry of this agreement. This agreement may be terminated
      before the expiry of the agreement only as under and subject to the
      consequences provided hereunder:
      a.   Termination of the Agreement by the Executive for following "Good
           reasons":
           i.   Sify breaching its obligations in paying compensation
           ii.  Sify demoting the Executive from his current position
           iii. Sify assigning duties to Executive inconsistent with his
                current/promoted positions
           iv.  Sify changing the location of the office of the Executive from
                Chennai
           v.   Within six months after Occurrence of a Change of control except
                if joining Satyam Computer Services Limited
      b.   Termination of the Agreement by Executive without assigning any
           reason.
      c.   Termination by Sify
      d.   Death of the Executive

      The parties agree that "Change of Control" means and includes:
      a.   Change in ownership structure of Sify from that prevalent on the date
           Executive commenced services with Sify or any date thereafter whereby
           any person or group of persons or entity or group of entities acquire
           in one or more transactions (i) beneficial ownership in Sify,
           directly or indirectly, in excess of 25% of the outstanding equity
           shares and becomes the largest group owning stock/shares in Sify or
           (ii) ability to command majority voting rights in Sify's Board of
           Directors.


<PAGE>


      b.   Sale or divestment (including through mergers, demergers,
           consolidations, acquisitions) of a substantial part of the assets or
           business of Sify whereby the majority owners of Sify prior to such
           sale/divestment don't receive majority ownership in the acquiring
           entity.

9.    In the event of death of the Executive, termination is effective on the
      date of death. In all other instances of termination before expiry of the
      agreement, both parties agree to give a written notice to the other of
      intent to terminate the Agreement and the termination is effective six (6)
      months after the notice is received.

10.   Executive is entitled to full compensation and benefits (excluding the
      performance bonus) up to the date of termination of the Agreement.
      Executive is entitled to pro rated performance bonus up to the date of
      termination of the Agreement in the event termination notice is served by
      Executive for "Good reasons" or served by Sify within one year after
      Change of Control.

11.   Executive is entitled following additional terminal compensation of Base
      salary (as referred to in Clause 4a) in the event of termination by Sify
      for any reason or by Executive for Good Reasons:
      a.   If notice of termination is served within 1 year from the date of
           this agreement or 1 year after a change of Control, 1 year Base
           salary
      b.   In all other circumstances, 6 months Base salary

12.   Executive has been provided by Sify a loan of Rs. 100 lakhs which is
      repayable by the Executive with interest on 31 December 2002. In
      consideration of the Executive agreeing to continue in the employment of
      Sify as aforesaid, Sify agrees to pay the Executive an Additional
      Compensation sufficient to repay the loan (income tax to Executive's
      account) and an Additional Compensation sufficient to pay the interest
      (income tax to Sify's account), at the earliest of the following
      circumstances:
      a.   On the loan falling due for repayment
      b.   On the occurrence of a Change of Control
      c.   On the death of the Executive
      (such Additional Compensation referred above shall be reduced by the value
      as on the date of such Additional Compensation of specified market liquid
      stock options granted before 31.12.2000, vested until that date).

13.   This Agreement is subject to the laws of India.

14.   It is the intent of both the parties to render this agreement enforceable
      to the fullest extent permitted by law. Any clause that turns out to be
      invalid should not render the entire agreement invalid.


For Satyam Infoway Limited




Mr. S. Srinivasan                                      Mr. T.R. Santhanakrishnan
Director                                               Chief Financial Officer


<PAGE>


                         EXECUTIVE EMPLOYMENT AGREEMENT


                             ANNEXURE A BASE SALARY

<TABLE>
<CAPTION>
<S>                                                <C>
Salary:
Basic salary          Rs lakhs per annum           15,99,600.00
Special allowance                                  12,18,364.00
House Rent allowance                                7,99,800.00

Perquisites/benefits:
Provision of Company car                           Yes
Conveyance expenses                                   72,000.00
Driver's salary                                       42,000.00
Vehicle maintenance expenses                          24,000.00
Medical expenses                                      15,000.00
Leave travel expenses                               1,33,300.00
Provident fund contribution                         1,91,952.00
Gratuity                                              63,984.00

Total Base Salary     Rs lakhs per annum           41,60,000.00


                          ANNEXURE B PERFORMANCE BONUS

Bonus payable on accomplishment of
KRA/KPI               Rs lakhs per annum           15,00,000.00
</TABLE>