<PAGE>

                                                                    Exhibit 10.9
                                                                    ------------

                             EMPLOYMENT AGREEMENT

     THIS EMPLOYMENT AGREEMENT (this "Agreement") is entered into as of June 26,
1999, by and between IFX CORPORATION, a Delaware corporation ("IFX" and,
collectively with its subsidiaries, "Employer"), and JOSE LEIMAN ("Employee").

                             W I T N E S S E T H:
                             -------------------

     WHEREAS, Employer desires to employ Employee on the terms and subject to
the conditions set forth herein; and

     WHEREAS, Employee has had an opportunity to review the terms and conditions
of this Agreement, to negotiate the terms hereof and to engage legal counsel on
his behalf if he so desires.

     NOW THEREFORE, in consideration of Employer's employment of Employee, the
terms, conditions and covenants contained herein and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
Employee and Employer, intending to be legally bound, hereby agree as follows:

     1.   Employment.  Employer hereby agrees to employ Employee and Employee
          ----------
agrees to accept such employment upon the terms and conditions herein set forth.

     2.   Employment Period.
          -----------------

          (a)  The term of employment hereunder shall commence on July 1, 1999,
and shall expire on June 30, 2001.
<PAGE>

     3.   Position and Duties.
          -------------------

          (a)  Position. Employee hereby agrees to serve as the Chief Financial
               --------
Officer of IFX. Employee shall devote his best efforts and full business time
and attention to the performance of services to Employer in accordance with the
terms hereof and as may reasonably be requested by the Board of Directors of
Employer (the "Board") or a person or persons designated by the Board. Employer
shall retain full direction and control of the means and methods by which
Employee performs the above services.

          (b)  Other Activities. During the Employment Period, Employee shall
               ----------------
not engage in any other business or professional activities, either on a full-
time or part-time basis, as an employee, consultant or in any other capacity,
whether or not he receives any compensation therefor, without the prior written
consent of the Board; provided, however, that nothing herein shall prevent
Employee from making and managing personal investments consistent with Sections
10 and 11 of this Agreement, or engaging in professional Bar Association or
Accounting Association activities so long as such activities, either singly or
in the aggregate, do not interfere with the proper performance of his duties and
responsibilities to Employer.

     4.   Compensation.
          ------------

          (a)  Base Salary. Employer shall pay to Employee salary at the rate of
               -----------
US$ 225,000 per year for the period from the date hereof through June 30, 2001
(the "Base Salary"). Payments of Base Salary shall be made in accordance with
Employer's generally applicable compensation policies and shall be net of
applicable tax withholdings.

          (b)  Bonus Compensation.  In addition to Base Salary, Employee shall
               ------------------
be entitled to receive bonus compensation based on the discretion of the Board
Of Directors. (the "Bonus Compensation").

          (c)  Holidays and Vacation Time. Employee shall be entitled to such
               --------------------------
paid holidays as are consistent with Employer's policy for executive employees
with respect to such matters as of the date hereof. Employee is entitled to four
(4) weeks of paid vacation per year, accruable monthly, but shall not be
entitled to carry-over into a following year any unused vacation time accrued at
year end.
<PAGE>

          (d)  Other Benefits. Subject to Employer's rules, policies and
               --------------
regulations as in effect from time to time (and subject to applicable
eligibility requirements, including a minimum employment period), Employee shall
be entitled to all other rights and benefits for which Employee may be eligible
under any: (i) group life insurance, disability or accident, death or
dismemberment insurance, (ii) medical and/or dental insurance program (90-day
minimum employment period, for which Employer will reimburse the COBRA expenses
of Employee), (iii) 401(k) benefit plan, or (iv) other employee benefits that
Employer may, in its sole discretion, make generally available to employees of
Employer of the same level and responsibility as Employee; provided, however,
that nothing herein shall obligate Employer to establish or maintain any of such
benefits or benefit plans. In addition, the Employee agrees that the Employee's
participation in the benefit programs described herein in this Section 4(d)
shall be at the Employee's discretion and the cost associated with such
participation will be reduced from the Base Salary.

          (e)  Life and Other Insurance. Subject to Employee meeting applicable
               ------------------------
underwriting criteria, Employer will provide term life and such other types of
insurance for Employee as shall be agreed upon between Employee and Employer
from time to time.

          (f)  Sign-on Bonus. Employer and Employee agree to negotiate in good
               -------------
faith to determine whether Employee is entitled to a sign-on bonus.

     5.   Participation in Stock Plan.
          ---------------------------

          (a)  Stock Plan Benefits. Subject to Employer's rules, policies and
               -------------------
regulations as in effect from time to time (and subject to applicable
eligibility requirements, including minimum employment period), Employee will be
eligible to receive certain benefits under the IFX Corporation 1998 Stock Option
and Incentive Plan or any other stock option plan adopted by IFX (the "Stock
Plan"). Employer represents that the shares to be issued under the Stock Plan
and on exercise of the options described below have been or will be registered
under a Form S-8 filed with the SEC. Benefits under the Stock Plan will be
granted in the sole and absolute discretion of the committee administering the
Stock Plan and shall be subject to the terms of the Stock Plan, as the same may
from time-to-time be amended and/or modified. In
<PAGE>

addition, the Employee shall receive the stock options described below in this
Section 5.

          (b)  Restrictions on Stock Plan Benefits. No options or other benefits
               -----------------------------------
shall be granted to Employee under the Stock Plan unless, in Employer's judgment
based on the advice of its legal counsel, such issuance complies with applicable
state and federal securities laws, and other laws and regulations related
thereto. All such Stock Plan benefits shall be subject to Employee signing such
option agreements or other instruments that Employer deems to be necessary or
appropriate and to such other restrictions as are required by the Stock Plan
and/or applicable law.

          (c)  Employee Stock Option Package. The Employee shall receive the
               -----------------------------
following IFX stock options under the Stock Plan, which shall be exercisable at:
a) the strike price of US$12 (the "Strike Price") multiplied by b) a multiple
(the "Multiple") as described herein.


        Description              Number Of Options           Multiple
      Year 1 Options                  25,000                   1.00
      Year 2 Options                  25,000                   1.25
      Year 3 Options                  25,000                   1.50
      Year 4 Options                  25,000                   1.75


In the absence of a Triggering Event, the stock options issued under this
Section 5(c) will vest in accordance with the following schedule:


            Description                       Vesting Period
          Year 1 Options             12 months from start of employment
          Year 2 Options             24 months from start of employment
          Year 3 Options             36 months from start of employment
          Year 4 Options             48 months from start of employment


Any unvested stock options granted pursuant to this Section 5(c) will become
fully vested upon the occurrence of any one of the following triggering events
(the "Triggering Events"): (i) employment is terminated by Employer other than
for Cause (as defined herein), (ii) Employee terminates
<PAGE>

employment with Good Reason (as defined herein), (iii) a Change in Control (as
defined herein), (iv) the term of employment hereunder expires on June 30, 2001
and a new employment agreement is not entered into by the parties, or (v) death
or disability of Employee. On the occurrence of a Triggering Event other than a
Change of Control, Employee's options, while vested, may not be exercised any
sooner than such options would have been exercisable in the absence of such
Triggering Event. On the occurrence of a Change of Control, Employee's options
shall vest and be exercisable effective prior to the Change of Control. The
stock options will automatically adjust the number of shares subject to options
in the event of a stock dividend, split-up, conversion, exchange,
reclassification or substitution. Any unexercised options will be forfeited by
Employee in the event that Employee is terminated for Cause (but not if Employee
voluntarily terminates with or without Good Reason).


     6.   Termination of Employment.
          -------------------------

          (a)  Permanent Disability. In the event of the Permanent Disability
               --------------------
(as defined below) of Employee, the Company, in its sole discretion, may elect
either (i) to the extent feasible consistent with Employee's mental and physical
condition and consistent with applicable law, to reassign Employee to other
duties within the Company that Employee is able to perform despite his Permanent
Disability at the compensation and benefit levels commensurate with Employee's
reassigned duties, unless that compensation level is less than the amount
payable in the event of a termination pursuant to the following sentence, or
(ii) to terminate this Agreement and Employee's employment hereunder. In the
event that the Company elects to terminate Employee as provided in clause (ii)
above, the Company shall, subject to following sentence, pay to Employee (A)
within sixty (60) days after the date of such termination, all amounts of Base
Salary accrued pursuant to Section 4 above prior to the date of such
termination, and (B) compensation on the basis of 65% of the then current Base
Salary for the first ninety (90) days of such Permanent Disability and,
thereafter, compensation on the basis of 50% of the then current Base Salary
through the end of the Permanent Disability period. This benefit may be provided
by the Company to Employee through the purchase of a disability insurance policy
that is contingent upon the insurability of Employee. Notwithstanding the
foregoing, all payments hereunder shall end upon the earlier to occur of
Executive's attaining the age of sixty-five (65) and the cessation of such
Permanent Disability (whether as a result of recovery, rehabilitation, death or
otherwise), and, thereafter, the Company shall have no further obligations to
Employee
<PAGE>

under this Agreement. Additionally, if prior to the termination of the Company's
obligation to make payments to Employee pursuant to this Section 6(a) Employee
receives compensation for services rendered, whether as an employee or
otherwise, such compensation shall reduce the payments due under this Section
6(a), dollar for dollar. Employee shall promptly inform the Company of all such
compensation received by him on a monthly basis during such period.

          (b)  Death. In the event of Employee's death, the Company shall pay to
               -----
Employee's personal representative (on behalf of Employee's estate), within
sixty (60) days after the Company receives written notice of such
representative's appointment, all amounts of Base Salary accrued pursuant to
Section 4 above as of the date of Employee's death and any amounts payable
pursuant to Section 5(c)(vi), which payment shall constitute full and complete
satisfaction of the Company's obligations hereunder except for any additional
payments subsequently due with respect to the exercise of options granted
pursuant to Section 5.  Employee's dependents shall also be entitled to any
continuation of health insurance coverage rights, if any, under applicable law.

          (c)  Termination for Cause or Voluntary Termination Without Good
               -----------------------------------------------------------
Reason. The Company may in its sole discretion terminate this Agreement and
------
Employee's employment with the Company for Cause (as defined in Section 7(a)
below) at any time with 30 days advance notice to Employee.  If Employee's
employment is terminated for Cause, or if Employee Voluntarily Terminates (as
defined in Section 7(b) below) his employment with the Company without Good
Reason (as defined in Section 7(c) below), the Company shall promptly pay to
Employee all amounts of Base Salary accrued pursuant to Section 4 above through
the date of termination (but not Bonus Compensation), whereupon the Company
shall have no further obligations to Employee under this Agreement. Employee
and his dependents shall also be entitled to any continuation health insurance
coverage rights, if any, under applicable law.  Without waiving any rights the
Company or any of its affiliates may have hereunder or otherwise, the Company
hereby expressly reserves its right to proceed against Employee for damages in
connection with any claim or cause of action that the Company may have arising
out of or related to Employee's employment hereunder.  In the event the Company
terminates Employee's employment for Cause or Employee voluntarily terminates
his employment without Good Reason, all unvested options and other awards
granted to Employee under the Stock Plan, as Bonus Compensation or otherwise
shall be cancelled and forfeited by Employee.
<PAGE>

          (d)  Termination Without Cause; Voluntary Termination With Good
               ----------------------------------------------------------
Reason. Subject to the penultimate sentence of this paragraph, the Company may
------
terminate this Agreement and Employee's employment with the Company without
Cause at any time, with or without notice, for any reason or no reason (and no
reason need be given). Employee may terminate this Agreement and Voluntarily
Terminate his employment with the Company with Good Reason upon thirty (30)
days' prior written notice to the Company, provided that the Company does not
correct the circumstances giving Employee Good Reason during such thirty (30)
day period. In the event Employee's employment with the Company is terminated
pursuant to this Section 6(d): (i) the Company shall immediately pay to Employee
in a lump sum all amounts of Base Salary for the entire length of the Term, (ii)
Employee shall be relieved of his obligations under Sections 1 and 3 hereof, and
(iii) Employee shall be free to seek other employment subject to the terms of
Sections 8, 9, 10 and 11 hereof. Employee and his dependents shall also be
entitled to any continuation health insurance coverage rights, if any, under
applicable law.

          (e)  Termination Obligations.
               -----------------------

     (i)  Employee hereby acknowledges and agrees that all personal property and
equipment furnished to or prepared by Employee in the course of or incident to
his employment by the Company, belongs to the Company and shall be promptly
returned to the Company upon termination of the Employee's employment. The term
"personal property" includes, without limitation, all books, manuals, records,
reports, notes, contracts, requests for proposals, bids, lists, blueprints, and
other documents, or materials, or copies thereof (including computer files), and
all other proprietary information relating to the business of the Company or any
of its affiliates. Following termination, Employee will not retain any written
or other tangible material containing any proprietary information of the Company
or any of its affiliates.

          (ii)   Upon termination of the Employment Period, Employee shall be
deemed to have resigned from all offices and directorships then held with the
Company and each of its affiliates.

          (iii)  The representations and warranties contained herein made by
either Employer and Employee and Employee's obligations under Sections 6(e), 8,
9, 10 and 11 shall survive termination of the Employment Period and the
expiration of this Agreement.
<PAGE>

          (iv)   If the common Closing price of the stock of Employer (or any
successor to Employer) equals or exceeds 100% of the exercise price of any
options granted pursuant to Section 4(b) hereof for 5 consecutive trading days
after the termination of Employee's employment, any options held by Employee
must be exercised within 90 days after the end of such 5 day period. Any options
which are not exercised at the end of such 90 day period will be forfeited by
Employee.

          (f)    Change of Control.  In the event of a Change of Control (as
                 -----------------
defined below), an amount equal to Employee's Base Salary shall be multiplied by
a factor of 2 and shall be paid by Employer (or its permitted successors) in one
lump-sum within 30 days after the effective date of the Change of Control.  In
addition, if so requested by Employee in writing at least 15 days prior to the
effective date of the Change of Control, Employer (or its permitted successors)
will either repurchase Employee's options within five (5) business days after
the effective date of the Change of Control or will cause employee's options to
be so repurchased at fair market value (as determined by Employer's regular
outside accounting firm).  Employer will give Employee reasonable notice of any
pending Change of Control (to the extent feasible under applicable securities
laws) in the event that Employee is not then employed by Employer.

     7.   Definitions.  For the purposes of this Agreement the following terms
          -----------
and phrases shall have the following meanings:

          (a)    "Business" shall mean the acquisition of internet service
                  --------
     providers in Latin America.

          (b)    "Cause".  The Company shall have "Cause" to terminate the
                  -----
     Employee's employment under this Agreement upon (a) the willful and
     continued failure by the Employee to substantially perform his duties under
     this Agreement (other than any failure resulting from the Employee's
     incapacity due to physical or mental illness) for one hundred twenty (120)
     days after written demand for substantial performance is delivered by the
     Company specifically identifying the manner in which the Company believes
     the Employee has not substantially performed his duties, or (B) the willful
     engaging by the Employee in criminal misconduct (including embezzlement and
     criminal fraud) which is materially injurious to the Company, or (C) the
     willful violation by the Employee of
<PAGE>

     Sections 8, 9, 10 or 11 of this Agreement, provided that the violation
     results in material injury to the Company, or (D) the conviction of the
     Employee of a felony. For purposes of this paragraph, no act, or failure to
     act, by the Employee shall be considered "willful" unless done or permitted
     to be done, by him not in good faith and without reasonable belief that his
     action or omission was in the interest of the Company. The Employee shall
     not be deemed to have been terminated for Cause unless and until there
     shall have been delivered to the Employee a copy of a resolution, duly
     adopted by the affirmative vote of a majority of the Board of the Company
     at a meeting of the Board called and held for such purposes (after a
     reasonable notice to the Employee and an opportunity for him, together with
     his counsel, to be heard before the Board), finding that in the good faith
     opinion of the Board the Employee was guilty of conduct set forth above in
     clause (A), (B), (C), or (D) and specifying the particulars of the conduct
     in detail.

          (c)    "Change of Control" shall mean: (i) the dissolution or
                  -----------------
     liquidation of the Employer, (ii) either A) the occurrence of a merger or
     consolidation, B) a transaction in which the Employer becomes a subsidiary
     of another corporation, and in either case, in which the voting securities
     of the Employer which are outstanding immediately prior thereto do not
     continue to represent (either by remaining outstanding or by being
     converted into voting securities of the surviving entity) more than 50% of
     the combined voting securities of the Employer or such surviving entity
     immediately after such merger or consolidation, (iii) such time that Lee S.
     Casty and his affiliates and International Technology Investments, LC
     ("ITI") and its affiliates own less than one-third of the outstanding
     voting securities of the Employer (determined as if the option held by ITI
     were exercised), (iv) an acquisition by a person or entity of voting
     securities of the Employer entitling such person to the same voting power
     (or greater voting power) as held by Lee S. Casty and ITI combined
     (determined as if the option held by ITI were exercised); or (v) the sale
     of all or substantially all of the assets of the Employer.

          (d)    "Good Reason" shall mean, with respect to a Voluntary
                  -----------
     Termination, if (i) such Voluntary Termination promptly follows a permanent
     material reduction of Employee's duties and responsibilities or a permanent
     change in Employee's duties and responsibilities such that Employee's
     duties and responsibilities are materially inconsistent with the type of
     duties and responsibilities of Employee in effect immediately
<PAGE>

     prior to such reduction or change, (ii) such Voluntary Termination promptly
     follows a material reduction in Employee's benefits if such reduction
     results in Employee's receiving benefits which are, in the aggregate, less
     than the benefits received by other comparable employees of the Company
     generally, (iii) the Company is in material breach of its payment
     obligations under this Agreement, which breach has not been cured within
     fifteen (15) days following the Company's receipt of written notice
     thereof, (iv) the Company is in violation of federal, state, or foreign law
     or regulation which has or could reasonably, if publicly disclosed,
     materially adversely affect the Company or the business reputation of the
     Company, unless Employee is principally responsible for such violation of
     law, and such violation has not been cured within sixty (60) days following
     the Company's receipt of written notice thereof, or (v) the Board of
     Directors of the Company otherwise determines that a Voluntary Termination
     by Employee is for "Good Reason" under the circumstances then prevailing.

          (e)    "Permanent Disability" shall have the meaning set forth in
                  --------------------
     Section 22(e)(3) of the Internal Revenue Code of 1986, as amended.

          (f)    "Voluntary Termination" (including "Voluntarily Terminates")
                  ---------------------
     shall mean the termination by Employee of his employment by the Company by
     voluntary resignation or any other means other than death, retirement or
     Permanent Disability and other than simultaneous with or following
     termination for Cause or an event which, whether or not known to the
     Company at the time of such Voluntary Termination by such Executive, would
     constitute Cause.

     8.   Records and Confidential Data.
          -----------------------------

          (a)    Employee acknowledges that, in connection with the performance
of his duties during the term of this Agreement, the Company and its affiliates
will make available to Employee, and/or Employee will have access to, certain
Confidential Information (as defined below) of the Company and its affiliates.
Employee acknowledges and agrees that any and all Confidential Information
learned or obtained by Employee during the course of his employment by the
Company or otherwise (including, without limitation, information that Employee
obtained through or in connection with his ownership of equity interests in, or
services as a director of, the Company), whether developed by Employee alone or
in conjunction with others or
<PAGE>

otherwise, shall be and is the property of the Company and its affiliates.

          (b)  The Confidential Information shall be kept confidential by
Employee unless disclosure is required by government regulation, subpoena or
other legal process, shall not be used in any manner which is detrimental to the
Company or any of its affiliates, shall not be used other than in connection
with Employee's discharge of his duties hereunder, and shall be safeguarded by
Employee from unauthorized disclosure.

          (c)  Following the first to occur of the termination of this Agreement
or Employee's termination hereunder, as soon as possible after the Company's
written request, Employee shall return to the Company all written Confidential
Information which has been provided to Employee and Employee shall destroy all
copies of any analyses, compilations, studies or other documents prepared by
Employee or for Employee's use containing or reflecting any Confidential
Information.  Within five (5) business days of the receipt of such request by
Employee, Employee shall, upon written request of the Company, deliver to the
Company a notarized document certifying that such written Confidential
Information has been returned or destroyed in accordance with this Section 8(c).

          (d)  For the purposes of this Agreement, "Confidential Information"
shall mean all confidential and proprietary information of the Company and/or
its affiliates, including, without limitation, information derived from reports,
investigations, experiments, research, trade secrets, work in progress, drawing,
designs, plans, proposals, requests for proposals, bids, codes, marketing and
sales programs, client lists, client mailing lists, medical, psychological,
academic and other records and reports, supplier lists, financial projections,
cost summaries, payor information, pricing formulae, marketing studies relating
to prospective business opportunities and all other concepts, ideas, materials,
or information prepared for performed for or by the Company and/or any of its
affiliates.  For purposes of this Agreement, the Confidential Information shall
not include and Employee's obligations under this Section 8 shall not extend to
(i) information which is generally available to the public, (ii) information
obtained by Employee from third persons not under agreement to maintain the
confidentiality of the same and (iii) information which is required to be
disclosed by law or legal process (after giving the Company prior written notice
thereof and an opportunity to contest such disclosure).  Without in any way
limiting the foregoing, "Confidential Information" also includes all information
relating to any options or other awards granted to Employee, pursuant to the
Stock Plan or otherwise, including the amount of any such
<PAGE>

award, the exercise price and the rate of vesting thereof.

          (e)  Employee hereby acknowledges that each subsidiary and affiliate
of Employer is expressly made a third party beneficiary hereto for purposes of
protecting its rights and interests hereunder.

     9.   Inventions and Other Matters.
          ----------------------------

          (a)  Employee agrees that all ideas, inventions, discoveries or
improvements made during the period of Employee's employment with Employer,
including, without limitation, new machines, devices, computer software
(including source code, operating systems and specifications, data, data bases,
files documentation and other materials related thereto), programs, processes,
uses, apparatuses, specialized information relating in any way to or that is
useful in the business or products of Employer or Employer's actual or
demonstrably anticipated research or development, designs or compositions of any
kind that Employee, individually or with others, may originate or develop while
employed by Employer (collectively, "Inventions"), shall belong to and be the
sole property of Employer and shall constitute works specially ordered or
commissioned as "works made for hire" under the United States Copyright Act and
other applicable law.  Without limiting the foregoing, Employee hereby assigns
and transfers to Employer all rights of whatever nature that Employee may have,
including, without limitation, any patent, trade secret, trademark or service
mark rights (and any goodwill appurtenant thereto), any rights of publicity and
any right, title and interest in any copyright and any right that may affix
under any copyright law now or hereinafter in force and effect in the United
States of America or in any other country or countries, in and to any Invention.
Employee acknowledges and agrees that Employer shall have the royalty-free right
to use in its businesses, and to make and sell products, processes, programs,
systems designs, methods, formulas, apparatus, techniques, and services derived
from any Inventions (whether or not patentable or copyrightable), as well as all
improvements thereof or know-how related thereto.

          (b)  For purposes of this Agreement, an Invention shall be deemed to
have been "made during the period of Employee's employment" if, during such
period, the Invention was conceived, in part or in whole, or first actually
reduced to practice.  Employee agrees that any patent, copyright or trade mark
application filed by or for the benefit of Employee or any of his affiliates
within a year after termination of Employee's employment shall be presumed to
relate to
<PAGE>

an Invention made during the term of his employment and Employee shall have the
burden of proof to prove otherwise.

          (c)  This Section 9 shall not apply to an Invention for which no
equipment, supplies, facilities or Confidential Information (as defined below)
of Employer was used and that was developed entirely on Employee's own time,
unless (i) the invention relates in any way to or is useful in the business or
products of Employer, or Employer's actual or demonstrably anticipated research
or development, or (ii) results from any work performed by Employee for or on
behalf of Employer.

          (d)  Employee agrees, without further consideration, to (i) promptly
disclose each such Invention to Employer, to Employee's immediate supervisor and
to such other individuals as Employer may direct, (ii) execute and to join
others in executing such applications, assignments and other documents as may be
necessary or convenient to vest in Employer, or its designee, full title to each
such Invention and as may be necessary or convenient to obtain United States and
foreign patents and copyrights thereon, to the extent Employer may so choose in
its sole discretion, (iii) testify in any legal proceeding relative to such
Invention whenever requested to do so by Employer, and (iv) furnish all facts
relating to such Inventions or the history thereof.

          (e)  Employee agrees that he will not at any time, except as
authorized or directed by Employer, publish or disclose any information or
knowledge concerning any Inventions unless disclosure is required by government
regulation, subpoena or other legal process.

     10.  Non-Competition.
          ---------------

          (a)  Employer and Employee recognize that Employee has been retained
to occupy a position that constitutes part of the professional, management and
executive staff of Employer, whose duties will include the formulation and
execution of management policy. Employee, for and in consideration of the
payments, rights and benefits provided herein, agrees that so long as he is
employed by Employer and, if Employer terminates his employment for Cause or if
Employee voluntarily terminates without Good Reason his employment with
Employer, for a period of one (1) year thereafter, Employee shall not (i) work,
(ii) assist, (iii) own any interest, directly or indirectly and whether
individually or as a joint venturer, partner, member, officer, director,
shareholder, consultant, employee or otherwise, in or (iv) make a financial
investment,
<PAGE>

whether in the form of equity or debt, in any business that is substantially
competitive with the Business.

          (b)  Notwithstanding the foregoing, nothing herein shall prohibit
Employee from holding five percent (5%) or less of any class of voting
securities of any entity whose equity securities are listed on a national
securities exchange or regularly traded in the over-the-counter market and for
which quotations are readily available on the National Association of Securities
Dealers Automated Quotation system.  In addition, after the termination of
Employee's employment with Employer for any reason, nothing herein shall be
deemed to prohibit Employee from working with or owning an interest in a
professional services firm such as an accounting firm or law firm as long as
Employee does not directly or in a supervisory capacity provide services to any
business that is substantially competitive with the Business.

          (c)  If Employee is terminated for Cause or voluntarily terminates
employment without Good Reason, then upon the termination of Employee's
employment with Employer, and for one (1) year thereafter, Employee shall
immediately notify Employer of each employment or agency relationship entered
into by Employee, and each corporation, proprietorship or other entity formed or
used by Employee, the business of which is directly in competition with the
Business.  The provisions of this Section 10 shall survive termination of this
Agreement for any reason.

          (d)  Employee agrees that the restrictions contained in this Section
10 are reasonable as to time and geographic scope. Employee acknowledges that
Employer is in direct competition with all other companies that provide services
and products similar to Employer's products and services throughout the United
States, Latin America and other markets in which Employer may be conducting the
Business at the time Employee's employment with Employer is terminated, and
because of the nature of the Business, Employee agrees that the covenants
contained in this Section 10 cannot reasonably be limited to any smaller
geographic area.

     11.  Non-Solicitation and Non-Interference.
          -------------------------------------

          (a)  Employee acknowledges that Employer has invested substantial time
and effort in assembling its present staff of personnel.  Employee agrees that
so long as he is employed by Employer and, if Employer terminates his employment
for Cause or if Employee voluntarily terminates without Good Reason his
employment with Employer, for a period of one (1) year
<PAGE>

thereafter, Employee shall not either directly or indirectly employ, solicit for
employment, or advise or recommend to any other person that such other person
employ or solicit for employment, any of Employer's employees.

          (b)  Employee acknowledges that all customers of Employer, which
Employee has serviced or hereafter services during Employee's employment by
Employer and all prospective customers from whom Employee has solicited or may
solicit business while in the employ of Employer, shall be solely the customers
of Employer.  Employee agrees that so long as he is employed by Employer and, if
Employer terminates his employment for Cause or if Employee voluntarily
terminates without Good Reason his employment with Employer, for a period of one
(1) year thereafter, Employee shall not either directly or indirectly solicit
business, as to products or services competitive with the Business of Employer,
from any of Employer's customers with whom Employee had contact during his
employment with Employer.

          (c)  Employee agrees that so long as he is employed by Employer and,
if Employer terminates his employment for Cause or if Employee voluntarily
terminates without Good Reason his employment with Employer, for a period of one
(1) year thereafter, Employee shall not either directly or indirectly interfere
with any relationship between Employer and any of its suppliers, clients or
employees. Employee agrees that during such one (1) year period, he will not
influence or attempt to influence any of the customers or clients of Employer
not to do business with Employer.

          (d)  Employee agrees that the restrictions contained in this Section
11 are reasonable as to time and geographic scope because of the nature of the
Business and Employee agrees, in particular, that the geographic scope of this
restriction is reasonable because companies in the same industry as the Business
compete on a nationwide basis. Employee acknowledges that Employer is in direct
competition with all other companies that provide services and products similar
to Employer's products and services on an outsourced basis throughout the United
States, Latin America and other markets in which Employer may be conducting the
Business at the time Employee's employment with Employer is terminated and,
because of the nature of the Business, Employee expressly agrees that the
covenants contained in this Section 11 cannot reasonably be limited to any
smaller geographic area.

     12.  Employment Relationship.  The relationship between Employer and
          -----------------------
Employee is
<PAGE>

and shall be specifically limited to an employer/employee relationship. As a
result, nothing contained in this Agreement or relating to any past, present or
future relationship between Employee and Employer (employment or otherwise)
shall be construed as creating any partnership, joint venture,
trustee/beneficiary or other type of fiduciary or business relationship between
the parties.

     13.  Prior Obligations.  Employee represents and warrants that (a) Employee
          -----------------
has no obligation of confidence or other commitments to any previous employer or
any others that conflict with this Agreement or restrict Employee's field of
activities, and (b) no other agreement to which Employee is subject will
conflict with, prevent, be breached by, interfere with or in any manner affect
the terms and conditions of this Agreement.

     14.  Dedication Of Services.  Subject to the provisions of Section 3(b)
          ----------------------
hereof, Employee agrees that while employed with Employer, Employee shall devote
his entire productive time, ability and attention to the business of Employer
during Employer's normal business hours. Employee further agrees that during his
employment by Employer, Employee will not, without Employer's prior written
consent, directly or indirectly engage in any employment, consulting, or other
activity which would conflict with Employee's duties and obligations to
Employer.

     15.  Jurisdiction; Service of Process.  Each of the parties hereto agrees
          --------------------------------
that all any action or proceeding initiated or otherwise brought to judicial
proceedings by either Employee or Employer concerning the subject matter of this
Agreement shall be litigated in the United States District Court for the
Southern District of Florida or, in the event such court cannot or will not
exercise jurisdiction, in the state courts of the State of Florida (the
"Courts"). Each of the parties hereto expressly submits to the jurisdiction and
venue of the Courts and consents to process being served in any suit, action or
proceeding of the nature referred to above either (a) by the mailing of a copy
thereof by registered or certified mail, postage prepaid, return receipt
requested, to his or its address as set forth herein (subject to notice of
change as set forth below) or (b) by serving a copy thereof upon such party's
authorized agent for service of process (to the extent permitted by applicable
law, regardless whether the appointment of such agent for service of process for
any reason shall prove to be ineffective or such agent for service of process
shall accept or acknowledge such service); provided that, to the extent lawful
and practicable, written notice of said service upon said agent shall be mailed
by registered or certified mail, postage prepaid, return receipt requested, to
the party at his or its address as set forth herein. Each party hereto agrees
that such service, to the
<PAGE>

fullest extent permitted by law, (i) shall be deemed in every respect effective
service of process upon him or it in any such suit, action or proceeding and
(ii) shall be taken and held to be valid personal service upon and personal
delivery to him or it. Each party hereto waives any claim that the Courts are an
inconvenient forum or an improper forum based on lack of venue or jurisdiction.
Each party shall bear its own costs and attorneys' fees incurred in connection
with any such actions or proceedings.

     16.  Injunctive Relief.  Employee acknowledge that damages would be an
          -----------------
inadequate remedy for Employee's breach of any of the provisions of Sections 8,
9, 10 and/or 11 of this Agreement, and that breach of any of such provisions
will result in immeasurable and irreparable harm to Employer. Therefore, in
addition to any other remedy to which Employer may be entitled by reason of
Employee's breach or threatened breach of any such provision, Employer shall be
entitled to seek and obtain a temporary restraining order, a preliminary and/or
permanent injunction, or any other form of equitable relief from any court of
competent jurisdiction restraining Employee from committing or continuing any
breach of such Sections, without the necessity of posting a bond. It is further
agreed that the existence of any claim or cause of action on the part of
Employee against Employer, whether arising from this Agreement or otherwise,
shall in no way constitute a defense to the enforcement of the provisions of
Sections 8, 9, 10 and/or 11 of this Agreement.

     17.  Indemnification. Employer agrees to indemnify Employee against
          ---------------
liabilities, expenses, and losses that may arise by reason of the Employee's
status as an officer and to advance expenses incurred as a result of any suit,
action, claim or proceeding, whether civil, criminal, investigative, or
administrative, against Employee. In addition, Employer agrees to maintain in
full force and effect, at its own expense, adequate insurance coverage
protecting the Employee and holding the Employee harmless against liabilities,
expenses, and losses arising from any suit, action, claim or proceeding, whether
civil, criminal, investigative, or administrative, made or asserted against the
Employee resulting from the Employee's actions in his official capacity. The
provisions of this Section 17 shall survive termination of this Agreement for
any reason.

     18.  Miscellaneous.
          -------------

          (a)  Notices.  All notices and other communications hereunder shall be
               -------
in writing and shall be deemed given (i) when made, if delivered personally,
(ii) three (3) days after being
<PAGE>

mailed by certified or registered mail, postage prepaid, return receipt
requested, or (iii) two (2) days after delivery to a reputable overnight courier
service, to the parties, their successors in interest or their assignees at the
following addresses, or at such other addresses as the parties may designate by
written notice in the manner aforesaid:

          To Employer:

          IFX Corporation
          200 West Adams Street
          Chicago, Illinois 60606
          Attention: President

          To Employee, to his home address as recorded in the payroll records of
          Employer from time to time, unless another address has been provided
          to Employer in writing by Employee.


          (b)  Governing Law.  This Agreement shall be governed as to its
               -------------
validity and effect by the internal laws of the State of Florida, without regard
to its rules regarding conflicts of law.

          (c)  Successors and Assigns.  This Agreement shall be binding upon and
               ----------------------
shall inure to the benefit of (i) the heirs, executors and legal representatives
of Employee, upon Employee's death or Permanent Disability and (ii) any
successor of Employer.  As used in this Agreement, "successor" shall include any
person, firm, corporation or other business entity that at any time, whether by
purchase, merger, consolidation or otherwise, directly or indirectly acquires a
majority of the assets, business or stock of Employer.

          (d)  Integration.  This Agreement (together with any option agreement
               -----------
Employer may require Employee to execute in order to avail himself/herself of
any Stock Plan benefits specifically contemplated herein and any agreement to
release and hold harmless Employer executed concurrently herewith) constitutes
the entire agreement between the parties with respect to all matters covered
herein, including but not limited to the parties' employment relationship and
Employee's entitlement to compensation, commissions and benefits from Employer
or any of its affiliated companies and/or the termination of Employee's
employment.  This Agreement supersedes all prior oral or written understandings
and agreements relating to its subject matter and
<PAGE>

all other business relationships between Employer and/or its affiliated
companies.

          (e)  No Representations.  No person or entity has made or has the
               ------------------
authority to make any representations or promises on behalf of any of the
parties which are inconsistent with the representations or promises contained in
this Agreement, and this Agreement has not been executed in reliance on any
representations or promises not set forth herein.  Specifically, no promises,
warranties or representations have been made by anyone on any topic or subject
matter related to Employee's relationship with Employer or any of its executives
or employees, including but not limited to any promises, warranties or
representations regarding future employment, compensation, commissions and
benefits, any entitlement to stock, stock rights, Stock Plan benefits, profits,
debt and equity interests in Employer or any of its affiliated companies or
regarding the termination of Employee's employment.  In this regard, Employee
agrees that no promises, warranties or representations shall be deemed to be
made in the future unless they are set forth in writing and assigned by an
authorized representative of Employer.

          (f)  Amendments.  This Agreement may be modified only by a written
               ----------
instrument executed by the parties that is designated as an amendment to this
Agreement.

          (g)  Counterparts.  This Agreement is being executed in one or more
               ------------
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

          (h)  Severability and Non-Waiver.  Any provision of this Agreement (or
               ---------------------------
portion thereof) which is deemed invalid, illegal or unenforceable in any
jurisdiction shall, as to that jurisdiction and subject to this Section, be
ineffective to the extent of such invalidity, illegality or unenforceability,
without affecting in any way the remaining provisions thereof in such
jurisdiction or rendering that or any other provisions of this Agreement
invalid, illegal, or unenforceable in any other jurisdiction.  If any covenant
should be deemed invalid, illegal or unenforceable because its scope is
considered excessive, such covenant shall be modified so that the scope of the
covenant is reduced only to the minimum extent necessary to render the modified
covenant valid, legal and enforceable.  No waiver of any provision or violation
of this Agreement by Employer shall be implied by Employer's forbearance or
failure to take action.

          (i)  Attorneys Fees.  In the event that any action or proceeding is
               --------------
commenced by
<PAGE>

any party hereto for the purpose of enforcing any provision of this Agreement,
the parties to such action, proceeding or arbitration may receive as part of any
award, settlement, judgment, decision or other resolution of such action or
proceeding, whether or not reduced to a court judgment, their costs and
reasonable attorneys fees as determined by the person or body making such award,
settlement, judgment, decision or resolution.

          (j)  Voluntary and Knowledgeable Act. Employee represents and warrants
               -------------------------------
that Employee has read and understands each and every provision of this
Agreement and has freely and voluntarily entered into this Agreement.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date first above written.

                                   EMPLOYER:

                                   IFX CORPORATION


                                   By:    /s/ Joel Eidelstein
                                          -------------------
                                   Name:  Joel Eidelstein
                                   Title: President



                                   EMPLOYEE:



                                   /s/ Jose Leiman
                                   -------------------
                                   Jose Leiman