<PAGE>

                                                                    EXHIBIT 10.2

                           THIRD AMENDED AND RESTATED

                          REGISTRATION RIGHTS AGREEMENT

                                      among

                                IFX CORPORATION,

                         UBS CAPITAL AMERICAS III, L.P.,

                                UBS CAPITAL LLC,

                   INTERNATIONAL TECHNOLOGY INVESTMENTS, LLC,

                                    LSC, LLC,

                                  JAK BURSZTYN

                                       and

                                  LEE S. CASTY

                            dated as of June 28, 2002

<PAGE>

                                                                    EXHIBIT 10.2

            THIRD AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

         THIS THIRD AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (this
"Agreement") is entered into as of June 28, 2002, among IFX Corporation, a
Delaware corporation (the "Company"), UBS Capital Americas III, L.P., a Jersey,
Channel Islands limited partnership, and UBS Capital LLC, a Delaware limited
liability company (together with their successors and assigns, collectively,
"UBS"), INTERNATIONAL TECHNOLOGY INVESTMENTS, LC, a Nevada limited liability
company ("ITI"), LSC, LLC ("LSC"), a Delaware limited liability company, JAK
BURSZTYN ("Bursztyn") and LEE S. CASTY (collectively with LSC, "Casty").

                                    RECITALS

         WHEREAS, the Company and UBS entered into that certain IFX Corporation
Preferred Stock Purchase Agreement, dated as of June 15, 2000, pursuant to which
UBS purchased 2,030,869 shares of Series A Convertible Preferred Stock, par
value $1.00 per share, of the Company (the "Series A Preferred Stock");

         WHEREAS, as a condition to and in consideration of UBS's purchase of
Series A Preferred Stock, the Company, UBS, ITI and Casty Grantor Subtrust
entered into that certain Registration Rights Agreement dated as of June 15,
2000;

         WHEREAS, the Company and UBS entered into that certain IFX Corporation
Preferred Stock Purchase Agreement, dated as of March 13, 2001, pursuant to
which UBS purchased 4,418,262 shares of Series B Convertible Preferred Stock,
par value $1.00 per share, of the Company (the "Series B Preferred Stock");

         WHEREAS, as a condition to and in consideration of UBS's purchase of
Series B Preferred Stock, the Company, UBS, ITI and Casty Grantor Subtrust
entered into that certain Amended and Restated Registration Rights Agreement,
dated May 7, 2001;

         WHEREAS, the Company and UBS entered into the IFX Corporation Series C
Convertible Preferred Stock Purchase Agreement, dated October 11, 2001, pursuant
to which UBS acquired 3,833,333 shares of newly issued Series C Convertible
Preferred Stock, par value $1.00 per share, of the Company (the "Series C
Preferred Stock");

         WHEREAS, as a condition to and in consideration of UBS's purchase of
Series C Preferred Stock, the Company, UBS, ITI and Casty entered into that
certain Second Amended and Restated Registration Rights Agreement, dated
February 19, 2002 (the "Existing Agreement");

         WHEREAS, the Company, UBS, ITI, Bursztyn and LSC have entered into the
IFX Corporation Series D Convertible Preferred Stock Purchase Agreement, dated
February 19, 2002 (the "Stock Purchase Agreement"), pursuant to which UBS, ITI,
Bursztyn and Casty will acquire shares of newly issued Series D Convertible
Preferred Stock, par value $1.00 per share, of the Company (the "Series D
Preferred Stock"); and

         WHEREAS, as a condition to and in consideration of the purchase of
Series D Preferred Stock by UBS, ITI, Bursztyn and LSC, the Company, the
Investor Stockholders and the

<PAGE>

Stockholders have agreed to amend and restate the Existing Agreement in the
manner set forth below.

         NOW THEREFORE, in consideration of the mutual covenants and agreements
contained in this Agreement and for other valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

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

         "Closing" has the meaning assigned to such term in the Stock Purchase
Agreement.

         "Commission" means the Securities and Exchange Commission or any other
federal agency then administering the federal securities laws.

         "Common Shares" means shares of Common Stock held by (i) ITI and Casty
and their permitted assigns under Section 13(b), (ii) the Investor Stockholders
or (iii) any other persons who acquire shares of Common Stock and become parties
to this Agreement pursuant to the last sentence of Section 13(a).

         "Common Stock" means the common stock, par value $0.02 per share, of
the Company and any securities issued in respect thereof, or in substitution
therefor, in connection with any stock split, dividend or combination, or any
reclassification, recapitalization, merger, consolidation exchange or other
similar reorganization.

         "Conversion Shares" means shares of Common Stock issued or issuable
upon conversion of the Preferred Shares.

         "Convertible Securities" shall mean (i) any rights, options or warrants
to acquire Common Stock or any capital stock of the Company or any Subsidiary,
including the Preferred Shares, and (ii) any notes, debentures, shares of
preferred stock or other securities, options, warrants or rights, which are
convertible or exercisable into, or exchangeable for, Common Stock or any
capital stock of the Company or any Subsidiary.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended,
or any similar federal statute, and the rules and regulations promulgated
thereunder.

         "Investor Stockholders" shall mean UBS, LSC, Bursztyn and ITI and any
other persons who acquire Preferred Shares and become parties to this Agreement
pursuant to the last sentence of Section 13(a).

         "Preferred Shares" shall mean the Company's Series A Preferred Stock,
Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and
any other class or series of preferred stock of the Company which is
convertible, directly or indirectly, into Common Stock, whether at the time of
issuance or upon passage of time or the occurrence of some future event.

         "Registration Expenses" means the expenses so described in Section 8.

                                       2

<PAGE>

         "Restricted Stock" means the Conversion Shares and Common Shares,
excluding Conversion Shares and Common Shares which have been (a) registered
under the Securities Act pursuant to an effective registration statement filed
thereunder and disposed of in accordance with the registration statement
covering them or (b) publicly sold pursuant to Rule 144 under the Securities
Act.

         "Securities Act" means the Securities Act of 1933, as amended, or any
similar federal statute, and the rules and regulations promulgated thereunder.

         "Selling Expenses" shall mean the expenses so described in Section 8.

         "Tutopia Put Agreement" has the meaning assigned to such term in the
Stock Purchase Agreement.

2.       Restrictive Legend. Each certificate representing Preferred Shares,
Conversion Shares or Common Shares shall, except as otherwise provided in this
Section 2 or in Section 3, be stamped or otherwise imprinted with a legend
substantially in the following form:

               "THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE
               SECURITIES ACT OF 1933 OR ANY STATE SECURITIES
               LAWS AND MAY NOT BE TRANSFERRED OR OTHERWISE
               DISPOSED OF UNLESS IT HAS BEEN REGISTERED UNDER
               SUCH ACT AND ALL SUCH APPLICABLE LAWS OR AN
               EXEMPTION FROM REGISTRATION IS AVAILABLE."

A certificate shall not bear such legend if in the opinion of counsel
satisfactory to the Company (it being agreed that each of Neal, Gerber &
Eisenberg and Kaye Scholer LLP shall be satisfactory) the securities represented
thereby may be publicly sold without registration under the Securities Act and
any applicable state securities laws.

3.       Removal of Legend. Each certificate for Preferred Shares, Conversion
Shares or Common Shares transferred shall bear the legend set forth in Section
2, except that such certificate shall not bear such legend if (i) such transfer
is in accordance with the provisions of Rule 144 (or any other rule permitting
public sale without registration under the Securities Act) or (ii) in the
opinion of counsel satisfactory to the Company (it being agreed that either of
Neal, Gerber & Eisenberg or Kaye Scholer LLP shall be satisfactory) the
transferee and any subsequent transferee would be entitled to transfer such
securities in a public sale without registration under the Securities Act.

4.       Required Registration. (a) At any time, UBS, ITI or Casty may request
the Company to register under the Securities Act all or any portion of the
shares of Restricted Stock held by such requesting holder or holders for sale in
the manner specified in such notice, provided that the shares of Restricted
Stock for which registration has been requested shall have a reasonably
anticipated aggregate price to the public which is at least $15,000,000 (the
"Minimum Offering Price"); provided further that neither ITI nor Casty shall
request such registration prior to a Qualified Public Offering without the
consent of UBS. The only securities which the Company shall be required to
register pursuant hereto shall be shares of Common Stock, provided, however,
that, in any underwritten public offering contemplated by this Section 4 or
Sections 5

                                       3

<PAGE>

and 6, the holders of Preferred Shares shall be entitled to sell such Preferred
Shares to the underwriters for conversion and sale of the shares of Common Stock
issued upon conversion thereof. Notwithstanding anything to the contrary
contained herein, the Company shall not be required to file any registration
statement under this Section 4, within such period of time after the effective
date of any earlier registration statement relating to an underwritten public
offering (other than a registration statement on Form S-3 or any successor
thereto relating to the resale of securities of the Company acquired in
connection with an acquisition or similar transaction (each, an "Acquisition
Registration Statement")) as shall be determined in good faith by the managing
underwriter of an underwritten public offering, provided that such time period
shall not exceed 180 days.

     (b) Following receipt of any notice under this Section 4, the Company shall
immediately notify all holders of Restricted Stock from whom notice has not been
received and shall use its reasonable best efforts to register under the
Securities Act, for public sale in accordance with the method of disposition
specified in such notice from requesting holders, the number of shares of
Restricted Stock specified in such notice (and in all notices received by the
Company from other holders within 30 days after the giving of such notice by the
Company). If such method of disposition shall be an underwritten public
offering, the Company shall designate the underwriter(s) of such offering,
subject to the approval by the holders of a majority of the shares of Restricted
Stock proposed to be sold in such offering, including the approval of UBS (such
approval not to be unreasonably withheld or delayed). If the managing
underwriter advises the Company in writing that in such underwriter's good faith
determination the marketing factors require a limitation of the amount of
Restricted Stock to be underwritten in such registration, the Company shall (to
the extent that the managing underwriter believes that such securities can be
sold in such offering without having an adverse effect upon the marketing of
such offering) register in such registration (i) first, the Restricted Stock
proposed to be sold by the parties participating in the demand registration of
Restricted Stock under this Section 4, pro rata based upon the number of shares
of Restricted Stock proposed to be sold by such holders; and (ii) second
securities held by the Company. The Company shall be obligated to register
Restricted Stock pursuant to this Section 4, in the case of registrations
requested by each of UBS, ITI and Casty on three occasions only, provided,
however, that such obligation shall be deemed satisfied only when a registration
statement covering all shares of Restricted Stock specified in demand notices
delivered pursuant to Section 4(a), for sale in accordance with the method of
disposition specified by the requesting holders, shall have become effective
and, if such method of disposition is a firm commitment underwritten public
offering, all such shares designated in the notice shall have been sold pursuant
thereto.

     (c) The Company shall, subject to Section 4(b), be entitled to include in
any registration statement referred to in this Section 4 for sale in accordance
with the method of disposition specified by the requesting holders, shares of
Common Stock to be sold by the Company for its own account.

5.   Incidental Registration. If the Company at any time (other than pursuant to
Section 4 or Section 6) proposes to register any of its securities under the
Securities Act for sale to the public, whether for its own account or for the
account of other security holders or both (except with respect to registration
statements on Forms S-4, S-8 or another form not available for registering the
Restricted Stock for sale to the public), each such time it will give written
notice to all holders of outstanding Restricted Stock of its intention so to do.
Upon the written request of any

                                       4

<PAGE>

such holder, received by the Company within 30 days after the giving of any such
notice by the Company, to register any of its Restricted Stock, the Company will
use its reasonable best efforts to cause the Restricted Stock as to which
registration shall have been so requested to be included in the securities to be
covered by the registration statement proposed to be filed by the Company, all
to the extent requisite to permit the sale or other disposition by the holder of
such Restricted Stock so registered. In the event that any registration pursuant
to this Section 5 shall be, in whole or in part, an underwritten public offering
of Common Stock, and the managing underwriter advises the Company in writing
that in such underwriter's good faith determination the marketing factors
require a limitation of the amount of Restricted Stock to be underwritten in
such registration then (a) if such registration is a primary registration on
behalf of the Company, the Company shall (to the extent that the managing
underwriter believes that such securities can be sold in such offering without
having an adverse effect upon the marketing of such offering) register in such
registration (i) first, the Company securities which the Company proposes to
sell in such registration, (ii) second, the Restricted Stock held by UBS and the
Conversion Shares held by Investor Stockholders other than UBS which they
propose to sell in such registration on a pro rata basis based upon the number
of shares of Restricted Stock held by UBS and Conversion Shares owned by
Investor Stockholders other than UBS, (iii) third, Restricted Stock held by ITI
and Casty and any other holders of Restricted Stock which they propose to sell
in such registration on a pro rata basis based upon the number of shares of
Restricted Stock owned by such holders and (iv) fourth, securities held by other
parties eligible for inclusion in such registration statement on a pro rata
basis based upon the amount of securities held by them, and (b) if such
registration is a secondary registration, the Company shall (to the extent that
the managing underwriter believes that such securities can be sold in such
offering without having an adverse effect upon the marketing of such offering)
register in such registration (i) first, the Restricted Stock held by UBS and
the Conversion Shares held by Investor Stockholders other than UBS which they
propose to sell in such registration on a pro rata basis based upon the number
of shares of Restricted Stock held by UBS and Conversion Shares owned by
Investor Stockholders other than UBS, (ii) second, the Restricted Stock held by
ITI and Casty and any other holders of Restricted Stock which they propose to
sell in such registration on a pro rata basis based upon the number of shares of
Restricted Stock owned by such holders and (iii) third, the securities held by
other parties eligible for inclusion in such registration on a pro rata basis
based upon the amount of securities held by them. Notwithstanding the foregoing
provisions, the Company may withdraw any registration statement referred to in
this Section 5, without thereby incurring any liability to the holders of
Restricted Stock other than for the payment of Registration Expenses in
accordance with Section 8.

6.   Registration on Form S-3. (a) Subject to the restrictions on transfer set
forth in Section 3.3 and 3.4 of the Stockholders Agreement (as defined in the
Stock Purchase Agreement), if at any time (i) UBS, ITI or Casty requests that
the Company file a registration statement on Form S-3 or any successor thereto
for a public offering of all or any portion of the shares of Restricted Stock
held by such requesting holder or holders, the reasonably anticipated aggregate
price to the public of which would exceed $2,500,000, provided that the
Restricted Stock for which registration has been requested constitutes at least
10% of the total shares of Restricted Stock then outstanding held by UBS, if
such registration is requested by UBS, or at least 10% of the total shares of
Restricted Stock then outstanding held by ITI or Casty, as the case may be, if
such registration is requested by ITI or Casty, and (ii) the Company is a
registrant entitled to use Form S-3 or any successor thereto to register such
shares, then the Company shall use its reasonable best efforts to register under
the Securities Act on Form S-3 or any successor thereto, for public

                                       5

<PAGE>

sale in accordance with the method of disposition specified in such notice, the
number of shares of Restricted Stock specified in such notice. Whenever the
Company is required by this Section 6(a) to use its reasonable best efforts to
effect the registration of Restricted Stock, each of the procedures and
requirements of Section 4 (including but not limited to the requirement that the
Company notify all holders of Restricted Stock from whom notice has not been
received and provide them with the opportunity to participate in the offering)
shall apply to such registration, provided, however, that the Company shall not
be obligated to effect more than two registrations on Form S-3 under this
Section in any calendar year, provided, further, that no request may be made by
a party under this Section 6(a) within 180 days after the effective date of any
other registration statement filed by the Company pursuant to this Section on
behalf of such party.

     (b) Notwithstanding Section 6(a) above, Casty may request, by written
notice, that the Company file a registration statement on Form S-3 or any
successor thereto for a public offering of all or any portion of the Restricted
Stock held by Casty (or any Affiliate thereof) (the "Eligible Shares") and if
the Company is a registrant entitled to use Form S-3 or any successor thereto to
register such shares, then the Company shall use its reasonable best efforts to
register under the Securities Act on Form S-3 or any successor thereto, for
public sale the number of shares of Restricted Stock specified in such written
notice to the Company (not to exceed the number of Eligible Shares); provided,
however, that (i) any registration under this Section 6(b) shall be a
non-underwritten offering; (ii) the Company shall not be obligated to effect
more than two registrations under this Section 6(b); (iii) the Company shall
only be obligated to effect one such registration during any calendar year
(which shall count as one of the two permitted in such calendar year pursuant to
Section 6(a)); and (iv) the Company shall not be required to maintain the
effectiveness of any such registration statement for more than 60 days.
Notwithstanding anything to the contrary contained herein, the Company shall not
be required to file any registration statement under this Section 6(b): (x)
within such period of time after the effective date of any earlier registration
statement relating to an underwritten public offering (other than an Acquisition
Registration Statement) as shall be determined in good faith by the managing
underwriter of an underwritten public offering, provided that such time period
shall not exceed 180 days or (y) if the Company shall furnish to Casty a
certificate signed by the President of the Company stating that in the good
faith judgment of the Board of Directors of the Company, it would be seriously
detrimental to the Company and its stockholders for such registration to be
effected at such time due to any pending material financing, acquisition or
corporate reorganization or other material corporate development involving the
Company or any of its subsidiaries.

7.   Registration Procedures. If and whenever the Company is required by the
provisions of Sections 4, 5 or 6 to use its reasonable best efforts to effect
the registration of any shares of Restricted Stock under the Securities Act, the
Company will, as expeditiously as possible:

     (a) prepare and file with the Commission a registration statement (which,
other than in the case of an underwritten public offering pursuant to Section 4,
may be on Form S-3 or any successor thereto if the Company is a registrant
entitled to use such Form) with respect to such securities and use its
reasonable best efforts to cause such registration statement to become and
remain effective for the period of the distribution contemplated thereby
(determined as hereinafter provided);

                                       6

<PAGE>

     (b) prepare and file with the Commission such amendments and supplements to
such registration statement and the prospectus used in connection therewith as
may be necessary to keep such registration statement effective for the period
specified in paragraph (a) above and comply with the provisions of the
Securities Act with respect to the disposition of all Restricted Stock covered
by such registration statement in accordance with the sellers' intended method
of disposition set forth in such registration statement for such period;

     (c) furnish to each seller of Restricted Stock and to each underwriter such
number of copies of the registration statement and the prospectus included
therein (including each preliminary prospectus) as such persons reasonably may
request in order to facilitate the public sale or other disposition of the
Restricted Stock covered by such registration statement;

     (d) use its reasonable best efforts to register or qualify the Restricted
Stock covered by such registration statement under the securities or "blue sky"
laws of such jurisdictions as the sellers of Restricted Stock or, in the case of
an underwritten public offering, the managing underwriter reasonably shall
request, provided, however, that the Company shall not for any such purpose be
required to qualify generally to transact business as a foreign corporation in
any jurisdiction where it is not so qualified or to consent to general service
of process in any such jurisdiction;

     (e) list the Restricted Stock covered by such registration statement with
any securities exchange on which the Common Stock of the Company is then listed;

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

     (g) as soon as practicable upon the occurrence of any event contemplated by
Section 7(f), prepare and file a supplement or post-effective amendment to such
registration statement or the prospectus contained in such registration
statement, or any document incorporated therein by reference, or file any other
required document so that, as thereafter delivered to the purchasers of the
shares of Restricted Stock covered thereby, the prospectus contained in such
registration statement will not contain any untrue statement of a material fact
or omit to state a material fact necessary to make the statements therein, in
the light of the circumstances under which they were made, not misleading;
provided, however, that the obligation to prepare and file any such supplement,
post-effective amendment or other document shall be suspended (a "Suspension")
if the Company shall furnish to the holders a certificate signed by the
President of the Company stating that in the good faith judgment of the Board of
Directors of the Company, it would be seriously detrimental to the Company and
its stockholders for such registration to be effected at such time due to any
pending material financing, acquisition or corporate reorganization or other
material corporate development involving the Company or any of its subsidiaries;
provided further, that the Company shall only be permitted to effectuate one (1)
Suspension in any twelve (12) month period and any such suspension will be
lifted by the Company as soon as practicable and will not, in any event, extend
for more than 60 days with respect to any such specified event;

                                       7

<PAGE>

     (h) if the offering is underwritten and at the request of any seller of
Restricted Stock, use its reasonable best efforts to furnish on the date that
Restricted Stock is delivered to the underwriters for sale pursuant to such
registration: (i) an opinion dated such date of counsel representing the Company
for the purposes of such registration, addressed to the underwriters and to such
seller, stating that such registration statement has become effective under the
Securities Act and that (A) to the best knowledge of such counsel, no stop order
suspending the effectiveness thereof has been issued and no proceedings for that
purpose have been instituted or are pending or contemplated under the Securities
Act, (B) the registration statement, the related prospectus and each amendment
or supplement thereof comply as to form in all material respects with the
requirements of the Securities Act (except that such counsel need not express
any opinion as to financial statements contained therein) and (C) to such other
effects as reasonably may be requested by counsel for the underwriters or by
such seller or its counsel and (ii) a letter dated such date from the
independent public accountants retained by the Company, addressed to the
underwriters and to such seller, stating that they are independent public
accountants within the meaning of the Securities Act and that, in the opinion of
such accountants, the financial statements of the Company included in the
registration statement or the prospectus, or any amendment or supplement
thereof, comply as to form in all material respects with the applicable
accounting requirements of the Securities Act, and such letter shall
additionally cover such other financial matters (including information as to the
period ending no more than five business days prior to the date of such letter)
with respect to such registration as such underwriters reasonably may request;
and

     (i) make available for inspection by each seller of Restricted Stock, any
underwriter participating in any distribution pursuant to such registration
statement, and any attorney, accountant or other agent retained by such seller
or underwriter, all financial and other records, pertinent corporate documents
and properties of the Company, and cause the Company's officers, directors and
employees to supply all information reasonably requested by any such seller,
underwriter, attorney, accountant or agent in connection with such registration
statement.

     Upon receipt of any notice from the Company of any event of the kind
described in Section 7.3(f), each seller of Restricted Stock (x) promptly will
discontinue disposition of any shares of Restricted Stock pursuant to such
registration statement until such seller of Restricted Stock has received copies
of the supplemented or amended prospectus contemplated by Section 7(g) (it being
understood that such discontinuance shall be deemed a Suspension subject to the
limitations on Suspensions set forth in Section 7(g)), (y) thereafter, will
utilize and distribute only such supplemented or amended prospectus, and (z) if
so directed by the Company, will deliver to the Company all copies of the
prospectus covering such shares of Restricted Stock in such party's possession
at the time of receipt of such suspension notice.

     For purposes of Section 7(a) and 7(b), the period of distribution of
Restricted Stock in a firm commitment underwritten public offering shall be
deemed to extend until each underwriter has completed the distribution of all
securities purchased by it, and the period of distribution of Restricted Stock
in any other registration shall be deemed to extend until the earlier of the
sale of all Restricted Stock covered thereby and 180 days following
effectiveness of registration.

     In connection with each registration hereunder, each seller of Restricted
Stock will furnish to the Company in writing such information with respect to
itself and the proposed distribution by it as reasonably shall be necessary in
order to assure compliance with federal and

                                       8

<PAGE>

applicable state securities laws, and will notify the Company promptly upon
the happening of any event during the period any registration statement is
effective that makes any statement regarding such seller made in a registration
statement or the prospectus contained therein untrue in any material respect or
which requires the making of any changes in a registration statement or the
prospectus contained therein in order to make the statements therein regarding
such seller, in light of circumstances under which they were made, not
misleading.

     In connection with each registration pursuant to Sections 4, 5 or 6
covering an underwritten public offering, the Company and each seller agree to
enter into a written agreement with the managing underwriter selected in the
manner herein provided in such form and containing such provisions as are
customary in the securities business for such an arrangement between such
underwriter and companies of the Company's size and investment stature.

8.   Expenses. All expenses incurred by the Company in complying with Sections
4, 5 and 6, including, without limitation, all registration and filing fees,
printing expenses, fees and disbursements of counsel and independent public
accountants for the Company, fees and expenses (including counsel fees) incurred
in connection with complying with state securities or "blue sky" laws, fees of
the National Association of Securities Dealers, Inc., transfer taxes, fees of
transfer agents and registrars, costs of insurance and reasonable fees and
disbursements of one counsel for the sellers of Restricted Stock, but excluding
any Selling Expenses, are called "Registration Expenses". If ITI, Bursztyn
and/or Casty are the only parties (other than the Company) selling Restricted
Stock pursuant to a registration statement described herein, "Registration
Expenses" shall not include the fees and disbursements of counsel for such
sellers of Restricted Stock. All underwriting discounts and selling commissions
applicable to the sale of Restricted Stock are called "Selling Expenses". The
Company will pay all Registration Expenses in connection with each registration
statement under Sections 4, 5 or 6.

9.   Indemnification and Contribution. (a) In the event of a registration of any
of the Restricted Stock under the Securities Act pursuant to Sections 4, 5 or 6,
the Company will indemnify and hold harmless each seller of such Restricted
Stock thereunder, each underwriter of such Restricted Stock thereunder and each
of their respective officers, directors, employees, partners, agents or other
person, if any, who controls such seller or underwriter within the meaning of
the Securities Act, against any losses, claims, damages or liabilities, joint or
several, to which such seller, underwriter or controlling person may become
subject under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon any untrue statement or alleged untrue statement of any material fact
contained in any registration statement under which such Restricted Stock was
registered under the Securities Act pursuant to Sections 4, 5 or 6, any
preliminary prospectus or final prospectus contained therein, or any amendment
or supplement thereof, or arise out of or are based upon the omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, and will reimburse each
such seller, each such underwriter and each such controlling person for any
legal or other expenses reasonably incurred by them in connection with
investigating or defending any such loss, claim, damage, liability or action,
provided, however, that the Company will not be liable in any such case if and
to the extent that any such loss, claim, damage or liability arises out of or is
based upon an untrue statement or alleged untrue statement or omission or
alleged omission so made in conformity with information furnished by any such
seller, any such underwriter or any

                                       9

<PAGE>

such controlling person in writing specifically for use in such registration
statement or prospectus and, provided further, however, that the Company will
not be liable to any such person or entity with respect to any such untrue
statement or omission or alleged untrue statement or omission made in any
preliminary prospectus that is corrected in the final prospectus filed with the
Commission pursuant to Rule 424(b) promulgated under the Securities Act (or any
amendment or supplement to such prospectus) if the person asserting any such
loss, claim, damage or liability purchased securities but was not given a copy
of the final prospectus (as amended or supplemented) at or prior to the written
confirmation of the sale of such securities to such person in any case where
such delivery of the final prospectus (as amended or supplemented) is required
by the Securities Act, unless such failure to deliver the final prospectus (as
amended or supplemented) was a result of the Company's failure to provide such
prospectus (as amended or supplemented).

     (b) In the event of a registration of any of the Restricted Stock under the
Securities Act pursuant to Sections 4, 5 or 6, each seller of such Restricted
Stock thereunder, severally and not jointly, will indemnify and hold harmless
the Company, each person, if any, who controls the Company within the meaning of
the Securities Act, each officer of the Company who signs the registration
statement, each director of the Company, each underwriter and each person who
controls any underwriter within the meaning of the Securities Act, against all
losses, claims, damages or liabilities, joint or several, to which the Company
or such officer, director, underwriter or controlling person may become subject
under the Securities Act or otherwise, insofar as such losses, claims, damages
or liabilities (or actions in respect thereof) arise out of or are based upon
any untrue statement or alleged untrue statement of any material fact contained
in the registration statement under which such Restricted Stock was registered
under the Securities Act pursuant to Sections 4, 5 or 6, any preliminary
prospectus or final prospectus contained therein, or any amendment or supplement
thereof, or arise out of or are based upon the omission or alleged omission to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading, and will reimburse the Company and each
such officer, director, underwriter and controlling person for any legal or
other expenses reasonably incurred by them in connection with investigating or
defending any such loss, claim, damage, liability or action, provided, however,
that such seller will be liable hereunder in any such case if and only to the
extent that any such loss, claim, damage or liability arises out of or is based
upon an untrue statement or alleged untrue statement or omission or alleged
omission made in reliance upon and in conformity with information pertaining to
such seller, as such, furnished in writing to the Company by such seller
specifically for use in such registration statement or prospectus, and provided,
further, however, that the liability of each seller hereunder shall be limited
to the proportion of any such loss, claim, damage, liability or expense which is
equal to the proportion that the public offering price of the shares sold by
such seller under such registration statement bears to the total public offering
price of all securities sold thereunder, but not in any event to exceed the net
proceeds received by such seller from the sale of Restricted Stock covered by
such registration statement.

     (c) Promptly after receipt by an indemnified party hereunder of notice of
the commencement of any action, such indemnified party shall, if a claim in
respect thereof is to be made against the indemnifying party hereunder, notify
the indemnifying party in writing thereof, but the omission so to notify the
indemnifying party shall not relieve it from any liability which it may have to
such indemnified party other than under this Section 9 and shall only relieve it
from any liability which it may have to such indemnified party under this
Section 9 if and to the

                                       10

<PAGE>

extent the indemnifying party is prejudiced by such omission. In case any such
action shall be brought against any indemnified party and it shall notify the
indemnifying party of the commencement thereof, the indemnifying party shall be
entitled to participate in and, to the extent it shall wish, to assume and
undertake the defense thereof with counsel satisfactory to such indemnified
party, and, after notice from the indemnifying party to such indemnified party
of its election so to assume and undertake the defense thereof, the indemnifying
party shall not be liable to such indemnified party under this Section 9 for any
legal expenses subsequently incurred by such indemnified party in connection
with the defense thereof other than reasonable costs of investigation and of
liaison with counsel so selected, provided, however, that, if the defendants in
any such action include both the indemnified party and the indemnifying party
and the indemnified party shall have reasonably concluded, based on advice of
counsel, that there may be reasonable defenses available to it which are
different from or additional to those available to the indemnifying party or if
the interests of the indemnified party reasonably may be deemed to conflict with
the interests of the indemnifying party, the indemnified party shall have the
right to select a separate counsel and to assume such legal defenses and
otherwise to participate in the defense of such action, with the reasonable
expenses and fees of such separate counsel and other reasonable expenses related
to such participation to be reimbursed by the indemnifying party as incurred.

     (d) In order to provide for just and equitable contribution in
circumstances in which the indemnity agreement provided for in Sections 9(a) and
9(b) above is for any reason held to be unenforceable by the indemnified party
although applicable in accordance with its terms, the Company and each holder of
Restricted Stock exercising rights under this Agreement shall contribute to the
aggregate losses, claims, damages and liabilities of the nature contemplated by
such indemnity agreement incurred by the Company and such holder, (i) in such
proportion as is appropriate to reflect the relative fault of the Company on the
one hand and such holder on the other, in connection with the statements or
omissions which resulted in such losses, claims, damages or liabilities or (ii)
if the allocation provided by clause (i) above is not permitted by applicable
law, in such proportion as is appropriate to reflect not only the relative fault
of, but also the relative benefits to, the Company on the one hand and such
holder on the other, in connection with the statements or omissions which
resulted in such losses, claims, damages or liabilities, as well as any other
relevant equitable considerations. The relative benefits to the indemnifying
party and indemnified party shall be determined by reference to, among other
things, the gross proceeds received by the indemnifying party and indemnified
party in connection with the offering to which such losses, claims, damages or
liabilities relate. The relative fault of the indemnifying party and indemnified
party shall be determined by reference to, among other things, whether the
action in question, including any untrue or alleged untrue statement of a
material fact or omission or alleged omission to state a material fact, has been
made by, or relates to information supplied by, the indemnifying party or the
indemnified party, and the parties' relative intent, knowledge, access to
information and opportunity to correct or prevent such action. The parties
hereto agree that it would not be just or equitable if contribution pursuant to
this Section 9(d) were determined by pro rata allocation or by any other method
of allocation which does not take account of the equitable considerations
referred to in the immediately preceding sentence. Notwithstanding the
provisions of this Section 9(d), each holder of Restricted Stock exercising
rights under this Agreement shall not be required to contribute any amount in
excess of the amount of the gross proceeds to such holder from sales of the
Restricted Stock of such holder under a registration statement.

                                       11

<PAGE>

     Notwithstanding the foregoing, no person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation. For purposes of this Section 9(d), each person, if
any, who controls a holder of Restricted Stock within the meaning of Section 15
of the Securities Act shall have the same rights to contribution as such holder,
and each director of the Company, each officer of the Company who signed a
registration statement and each person, if any, who controls the Company within
the meaning of Section 15 of the Act shall have the same rights to contribution
as the Company.

10.  Changes in Common Stock or Preferred Shares. If, and as often as, there is
any change in the Common Stock or the Preferred Shares by way of a stock split,
stock dividend, combination or reclassification, or through a merger,
consolidation, reorganization or recapitalization, or by any other means,
appropriate adjustment shall be made in the provisions hereof so that the rights
and privileges granted hereby shall continue with respect to the Common Stock or
the Preferred Shares as so changed.

11.  Rule 144 Reporting. With a view to making available the benefits of certain
rules and regulations of the Commission which may at any time permit the sale of
the Restricted Stock to the public without registration, the Company agrees to:

     (a) make and keep public information available, as those terms are
understood and defined in Rule 144 under the Securities Act;

     (b) use its reasonable best efforts to file with the Commission in a timely
manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act; and

     (c) furnish to each holder of Restricted Stock forthwith upon request a
written statement by the Company as to its compliance with the reporting
requirements of such Rule 144 and of the Securities Act and the Exchange Act, a
copy of the most recent annual or quarterly report of the Company, and such
other reports and documents so filed by the Company as such holder may
reasonably request in availing itself of any rule or regulation of the
Commission allowing such holder to sell any Restricted Stock without
registration.

12.  Representations and Warranties of the Company.  The Company represents and
warrants to UBS, ITI and Casty as follows:

     (a) The execution, delivery and performance of this Agreement by the
Company have been duly authorized by all requisite corporate action on its part
and will not violate any provision of law, any order of any court or other
agency of government, the Certificate of Incorporation or By-laws each, as
amended, of the Company or any provision of any indenture, agreement or other
instrument to which it or any or its properties or assets is bound, conflict
with, result in a breach of or constitute (with due notice or lapse of time or
both) a default under any such indenture, agreement or other instrument or
result in the creation or imposition of any lien, charge or encumbrance of any
nature whatsoever upon any of the properties or assets of the Company, except
where the foregoing would not reasonably be expected to have a material adverse
effect on the Company or its business.

                                       12

<PAGE>

     (b) This Agreement has been duly executed and delivered by the Company and
constitutes the legal, valid and binding obligation of the Company, enforceable
against the Company in accordance with its terms.

13.  Miscellaneous.(a) Except as otherwise provided herein, no modification,
amendment or waiver of any provision of this Agreement shall be effective
against the Company or any other party unless such modification, amendment or
waiver is approved in writing by the Company and the holders of at least 66 2/3%
of the outstanding shares of Restricted Stock held by each of UBS, ITI and
Casty; provided that any modification, amendment or waiver which would adversely
affect any party hereto in a manner which is different from the manner the other
parties hereto are affected shall also require the approval of such party. The
failure of any party to enforce any of the provisions of this Agreement shall in
no way be construed as a waiver of such provisions and shall not affect the
right of such party thereafter to enforce each and every provision of this
Agreement in accordance with its terms. The parties hereby consent to any
amendment to this Agreement solely to add as a party hereto any person acquiring
Preferred Shares after the date hereof pursuant to the Tutopia Put Agreement.

     (b) This Agreement shall bind and inure to the benefit of and be
enforceable by the parties hereto and their respective heirs, personal
representatives, successors and permitted assigns. This Agreement and the rights
of the parties hereunder may not be assigned by any party hereto without the
prior written consent of the other parties, except as otherwise provided herein.
The Investor Stockholders may assign all or any portion of their rights and
obligations hereunder to a transferee of Restricted Stock, provided that such
transferee agrees in writing to be bound by the provisions of this Agreement.
ITI, Bursztyn and Casty may assign all or any portion of their rights and
obligations hereunder to a transferee of Restricted Stock, provided that each
such transferee of ITI, Bursztyn and Casty and any subsequent transferee shall,
together with ITI, Bursztyn or Casty, as the case may be, be deemed one person
for purposes of this Agreement, and any right or notice hereunder on behalf of
such person may only be delivered by ITI, Bursztyn or by Casty and, provided,
further, that ITI, Bursztyn or Casty, as the case may be, shall provide notice
of any such assignment to the other parties hereto, and any such transferee must
agree in writing to be bound by the provisions of this Agreement.

     (c) All notices required or permitted hereunder shall be in writing and
shall be deemed effectively given: (i) upon personal delivery to the party to be
notified; (ii) when sent by confirmed facsimile if sent during normal business
hours of the recipient, if not, then on the next business day; (iii) five days
after having been sent by registered or certified mail, return receipt
requested, postage prepaid; or (iv) one business day after deposit with a
nationally recognized overnight courier, specifying next day delivery, with
written verification of receipt. All communications shall be sent, with respect
to the Company and the Investor Stockholders, to their respective addresses
specified in the Stock Purchase Agreement (or at such other address as any such
party may specify by like notice) and, with respect to any other party, to the
address of such party as shown in the stock record books of the Company (or at
such other address as any such party may specify to all of the above by like
notice).

     (d) Except as otherwise expressly set forth herein, this document, the
Stock Purchase Agreement and the documents executed in connection with the
closing of the Stock Purchase Agreement embody the complete agreement and
understanding among the parties hereto with respect to the subject matter hereof
and supersede and preempt any prior understandings,

                                       13

<PAGE>

agreements or representations by or among the parties, written or oral, that may
have related to the subject matter hereof in any way.

     (e) This Agreement shall be governed by and construed and enforced in
accordance with the internal laws of the State of New York without regard to the
principles of conflicts of law thereof. Each party hereto hereby irrevocably
submits to the nonexclusive jurisdiction of the courts of the state of New York
and of the United States of America sitting in the City of New York, Borough of
Manhattan, for the adjudication of any dispute hereunder or in connection
herewith or with any transaction contemplated hereby or discussed herein, and
hereby irrevocably waives, and agrees not to assert in any suit, action or
proceeding, any claim that it is not personally subject to the jurisdiction of
any such court, that the venue thereof may not be appropriate, that such suit,
action or proceeding is improper or that this Agreement or any of the documents
referred to in this Agreement may not be enforced in or by said courts, and each
party hereto irrevocably agrees that all claims with respect to such suit,
action or proceeding may be heard and determined in such a New York state or
federal court. Each party hereby irrevocably waives personal service of process
and consents to process being served in any such suit, action or proceeding by
mailing a copy thereof to such party in the manner provided in Section 12(b) of
the Stock Purchase Agreement and agrees that such service shall constitute good
and sufficient service of process and notice thereof. Nothing contained herein
shall be deemed to limit in any way any right to serve process in any manner
permitted by law. EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE,
AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE
HEREUNDER OR IN CONNECTION HEREWITH OR ARISING OUT OF THIS AGREEMENT OR ANY
TRANSACTION CONTEMPLATED HEREBY.

     (f) The obligations of the Company to register shares of Restricted Stock
under Section 4, 5 or 6 shall terminate at the time at which all Restricted
Securities are eligible for resale pursuant to Rule 144(k) under the Securities
Act.

     (g) If requested in writing by the Company and the underwriters for an
underwritten public offering of securities of the Company, each holder of
Restricted Stock who is a party to this Agreement shall agree not to sell
publicly any shares of Restricted Stock or any other shares of Common Stock
(other than shares of Restricted Stock or other shares of Common Stock being
registered in such offering), without the consent of the Company and such
underwriters, for such period requested by the underwriters (not to exceed 180
days) following the effective date of the registration statement relating to the
Qualified Public Offering (as defined in the Stock Purchase Agreement) or 90
days following the effective date of a registration statement relating to any
other offering; provided, however, that all persons entitled to registration
rights with respect to shares of Common Stock who are not parties to this
Agreement, all persons holding 5% or more of the capital stock of the Company on
a fully diluted basis and all executive officers and directors of the Company
shall also have agreed not to sell publicly their Common Stock under the
circumstances and pursuant to the terms set forth in this Section 13(g).

     (h) Notwithstanding the provisions of Section 7(a), the Company's
obligation to file a registration statement, or cause such registration
statement to become and remain effective, shall be suspended for a period not to
exceed 90 days in any 12-month period if the Company shall furnish to the
holders a certificate signed by the President of the Company stating that in the
good faith judgment of the Board of Directors of the Company, it would be
seriously detrimental

                                       14

<PAGE>

to the Company and its stockholders for such registration to be effected at such
time due to any pending material financing, acquisition or corporate
reorganization or other material corporate development involving the Company or
any of its subsidiaries; provided, however, that any suspension effectuated by
the Company under this Section 13(h) shall be deemed a Suspension subject to the
limitation on the number of Suspensions permitted in any twelve month period
under Section 7(g) hereof.

     (i)  The Company shall not grant to any third party any registration rights
more favorable than or inconsistent with any of those contained herein, so long
as any of the registration rights under this Agreement remains in effect.

     (j)  Whenever possible, each provision of this Agreement shall be
interpreted in such manner as to be effective and valid under applicable law,
but if any provision of this Agreement is held to be invalid, illegal or
unenforceable in any respect under any applicable law or rule in any
jurisdiction, such invalidity, illegality or unenforceability shall not affect
any other provision or any other jurisdiction, but this Agreement shall be
reformed, construed and enforced in such jurisdiction as if such invalid,
illegal or unenforceable provision had never been contained herein.

     (k)  The titles of the sections and subsections of this Agreement are for
convenience of reference only and are not to be considered in construing this
Agreement.

     (l)  This Agreement may be executed in any number of counterparts, each of
which shall be an original, but all of which together shall constitute one
instrument. This Agreement may be executed by facsimile signature(s).

                            [Signatures on Next Page]

                                       15

<PAGE>

         IN WITNESS WHEREOF, the parties have executed this THIRD AMENDED AND
RESTATED REGISTRATION RIGHTS AGREEMENT as of the date set forth in the first
paragraph hereof.

                                         IFX CORPORATION

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

                                         UBS CAPITAL AMERICAS III, L.P
                                             By:  UBS Capital Americas III, LLC

                                         By:/s/ Mark O. Lama
                                            ------------------------------------
                                            Name:  Mark O. Lama
                                            Title: Principal

                                         By:/s/ Marc Unger
                                            ------------------------------------
                                            Name:  Marc Unger
                                            Title: Chief Financial Officer

                                         UBS CAPITAL LLC

                                         By:/s/ Mark O. Lama
                                            ------------------------------------
                                            Name:  Mark O. Lama
                                            Title: Attorney-in-Fact

                                         By:/s/ Marc Unger
                                            ------------------------------------
                                            Name:  Marc Unger
                                            Title: Attorney-in-Fact

                                         INTERNATIONAL TECHNOLOGIES
                                         INVESTMENTS, LC

                                         By:/s/ Michael Shalom
                                            ------------------------------------
                                            Name:  Michael Shalom
                                            Title: Manager

                                       16

<PAGE>

                                         /s/ Lee S. Casty
                                         ---------------------------------------
                                         LEE S. CASTY

                                         LSC, LLC

                                         By:/s/ Lee Casty
                                            ------------------------------------
                                            Lee Casty, Manager

                                         /s/ Jak Bursztyn
                                         ---------------------------------------
                                         JAK BURSZTYN

                                       17