<PAGE>   1
                                                                     EXHIBIT 4.4

                                     WARRANT

THE WARRANT EVIDENCED OR CONSTITUTED HEREBY, AND ALL SHARES OF PREFERRED STOCK
ISSUABLE HEREUNDER AND COMMON STOCK ISSUABLE UPON THE CONVERSION OF THE
PREFERRED STOCK, HAVE BEEN AND WILL BE ISSUED WITHOUT REGISTRATION UNDER THE
SECURITIES ACT OF 1933, AS AMENDED ("THE ACT") AND MAY NOT BE SOLD, OFFERED FOR
SALE, TRANSFERRED, PLEDGED OR HYPOTHECATED WITHOUT REGISTRATION UNDER THE ACT
UNLESS EITHER (i) THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL, IN FORM AND
SUBSTANCE REASONABLY SATISFACTORY TO THE COMPANY, TO THE EFFECT THAT
REGISTRATION IS NOT REQUIRED IN CONNECTION WITH SUCH DISPOSITION OR (ii) THE
COMPANY IS REASONABLY SATISFIED THAT THE SALE OF SUCH SECURITIES IS MADE
PURSUANT TO SECURITIES AND EXCHANGE COMMISSION RULE 144.

   WARRANT TO PURCHASE SERIES E PREFERRED STOCK OF FORMUS COMMUNICATIONS, INC.

                             (Subject to Adjustment)

NO. 1

         THIS CERTIFIES THAT, for value received, Intel Corporation, or its
permitted registered assigns ("Holder"), is entitled, at any time or from time
to time after September 9, 1999 (the "Exercise Date") and before the expiration
date defined in Section 2.8 below (the "Expiration Date"), to purchase from
Formus Communications, Inc., a Delaware corporation (the "Company"), one million
two hundred and fifty thousand (1,250,000) shares of Warrant Stock (as defined
in Section 1 below) of the Company at a price per share of $13.50 (the "Purchase
Price"), subject to the vesting schedule listed in Attachment A hereto. Both the
number of shares of Warrant Stock purchasable upon exercise of this Warrant and
the Purchase Price are subject to adjustment and change as provided herein.

1.       CERTAIN DEFINITIONS. As used in this Warrant the following terms shall
have the following respective meanings:

         "Fair Market Value" of a share of Warrant Stock as of a particular date
shall mean:

                  (a) If traded on a securities exchange or the Nasdaq National
Market, the Fair Market Value shall be deemed to be the average of the closing
prices of the Warrant Stock of the Company on such exchange or market over the 5
business days ending immediately prior to the applicable date of valuation;

                  (b) If actively traded over-the-counter, the Fair Market Value
shall be deemed to be the average of the closing bid prices over the 30-day
period ending immediately prior to the applicable date of valuation; and

                  (c) If there is no active public market, the Fair Market Value
shall be the value thereof, as determined in good faith by the Company's board
of directors; provided, however,



<PAGE>   2

that if the Holder objects in good faith to such determination, then, such value
shall be determined by an independent valuation firm experienced in valuing
businesses such as that of the Company and jointly selected in good faith by the
Company and the Holder. Fees and expenses of the valuation firm shall be shared
equally by the Company and the Holder.



         "HSR Act" shall mean the Hart-Scott-Rodino Antitrust Improvements Act
of 1976.

         "IPO" shall mean the Company's first firm commitment underwritten
public offering of the Company's Common Stock pursuant to a registration
statement filed with the Securities and Exchange Commission.

         "Registered Holder" shall mean any Holder in whose name this Warrant is
registered upon the books and records maintained by the Company.

         "Warrant" as used herein, shall include this Warrant and any warrant
delivered in substitution or exchange therefor as provided herein.

         "Warrant Stock" shall mean the Series E Preferred Stock of the Company
and any other securities at any time receivable or issuable upon exercise of
this Warrant.

2.            EXERCISE OF WARRANT

         2.1. Payment. Subject to compliance with the terms and conditions of
this Warrant and applicable securities laws and subject to the vesting
conditions referenced in Section 2.8, this Warrant may be exercised, in whole or
in part at any time or from time to time, on or before the Expiration Date by
the delivery (including, without limitation, delivery by facsimile) of the form
of Notice of Exercise attached hereto as Exhibit 1 (the "Notice of Exercise"),
duly executed by the Holder, at the principal office of the Company, and as soon
as practicable after such date, surrendering

              (a) this Warrant at the principal office of the Company, and

              (b) payment, (i) in cash (by check) or by wire transfer, (ii) by
cancellation by the Holder of indebtedness of the Company to the Holder; or
(iii) by a combination of (i) and (ii), of an amount equal to the product
obtained by multiplying the number of shares of Warrant Stock being purchased
upon such exercise by the then effective Purchase Price (the "Exercise Amount"),
except that if Holder is subject to HSR Act Restrictions (as defined in Section
2.6 below), the Exercise Amount shall be paid to the Company within five (5)
business days of the termination of all HSR Act Restrictions.

         2.2. Net Issue Exercise. In lieu of the payment methods set forth in
Section 2.1(b) above, the Holder may elect to exchange all or some of the
Warrant for shares of Warrant Stock equal to the value of the amount of the
Warrant being exchanged on the date of exchange. If Holder elects to exchange
this Warrant as provided in this Section 2.2, Holder shall tender to the Company
the Warrant for the amount being exchanged, along with written notice of
Holder's election to exchange some or all of the Warrant, and the Company shall
issue to Holder the number of shares of Warrant Stock computed using the
following formula:

                                      -2-
<PAGE>   3

                  X = Y (A-B)
                      -------
                         A

                  Where X = the number of shares of Warrant Stock to be issued
                  to Holder.

                  Y = the number of shares of Warrant Stock purchasable under
                  the amount of the Warrant being exchanged (as adjusted to the
                  date of such calculation).

                  A = the Fair Market Value of one share of the Company's
                  Warrant Stock.

                  B = Purchase Price (as adjusted to the date of such
                  calculation).

         All references herein to an "exercise" of the Warrant shall include an
exchange pursuant to this Section 2.2.

         2.3. Initial Public Offering. Upon receipt of a written notice of the
Company's intention to raise capital by selling shares of Common Stock in an IPO
(the "IPO Notice"), which notice shall be delivered to Holder at least thirty
(30) but not more than ninety (90) days before the anticipated date of the
filing with the Securities and Exchange Commission of the registration statement
associated with the IPO, the Holder shall notify the Company within 15 days
after receiving the IPO Notice whether or not the Holder will exercise this
Warrant pursuant to Section 2.2 prior to consummation of the IPO. If the Holder
notifies the Company that it does not intend to exercise this Warrant before
consummation of the IPO or if the Holder does not give timely notice in response
to the IPO Notice, then the Holder will not be allowed to exercise this Warrant
until after consummation of the IPO and completion of the distribution of the
IPO shares or, if sooner, abandonment of the IPO by the Company. Notwithstanding
whether or not an IPO Notice has been delivered to Holder or any other provision
of this Warrant to the contrary, if Holder decides to exercise this Warrant
while a registration statement is on file with the Securities and Exchange
Commission (the "SEC") in connection with the IPO, this Warrant shall be deemed
exercised immediately prior to the consummation of the IPO and the Fair Market
Value of a share of Warrant Stock will be the price of the Common Stock of the
Company issuable upon conversion of the Warrant Stock as such Common Stock price
is stated in the final prospectus used in for the IPO. If Holder has elected to
exercise this Warrant pursuant to Section 2.2 while a registration statement is
on file with the Securities and Exchange Commission in connection with an IPO
and the IPO is not consummated, then Holder's exercise of this Warrant shall not
be effective unless Holder confirms in writing Holder's intention to go forward
with the exercise of this Warrant.

         2.4. "Easy Sale" Exercise. In lieu of the payment methods set forth in
Section 2.1(b) above, when permitted by law and applicable regulations
(including Nasdaq and NASD rules), the Holder may pay the Purchase Price through
a "same day sale" commitment from the Holder (and if applicable a broker-dealer
that is a member of the National Association of Securities Dealers (a "NASD
Dealer")), whereby the Holder irrevocably elects to exercise this Warrant and to
sell a portion of the Shares so purchased to pay for the Purchase Price and the
Holder (or, if applicable, the NASD Dealer) commits upon sale (or, in the case
of the NASD Dealer, upon receipt) of such Shares to forward the Purchase Price
directly to the Company.

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<PAGE>   4

         2.5. Stock Certificates; Fractional Shares. As soon as practicable on
or after such date, the Company shall issue and deliver to the person or persons
entitled to receive the same a certificate or certificates for the number of
whole shares of Warrant Stock issuable upon such exercise, together with cash in
lieu of any fraction of a share equal to such fraction of the current Fair
Market Value of one whole share of Warrant Stock as of the date of exercise of
this Warrant. No fractional shares or scrip representing fractional shares shall
be issued upon an exercise of this Warrant.

         2.6. HSR Act. The Company hereby acknowledges that exercise of this
Warrant by Holder may subject the Company and/or the Holder to the filing
requirements of the HSR Act and that Holder may be prevented from exercising
this Warrant until the expiration or early termination of all waiting periods
imposed by the HSR Act ("HSR Act Restrictions"). If on or before the Expiration
Date Holder has sent the Notice of Exercise to Company and Holder has not been
able to complete the exercise of this Warrant prior to the Expiration Date
because of HSR Act Restrictions, the Holder shall be entitled to complete the
process of exercising this Warrant in accordance with the procedures contained
herein notwithstanding the fact that completion of the exercise of this Warrant
would take place after the Expiration Date or the completion of the IPO.

         2.7. Partial Exercise; Effective Date of Exercise. In case of any
partial exercise of this Warrant, the Company shall cancel this Warrant upon
surrender hereof and shall execute and deliver a new Warrant of like tenor and
date for the balance of the shares of Warrant Stock purchasable hereunder. This
Warrant shall be deemed to have been exercised immediately prior to the close of
business on the date of its surrender for exercise as provided above. However,
if Holder is subject to HSR Act filing requirements this Warrant shall be deemed
to have been exercised on the date immediately following the date of the
expiration of all HSR Act Restrictions. The person entitled to receive the
shares of Warrant Stock issuable upon exercise of this Warrant shall be treated
for all purposes as the holder of record of such shares as of the close of
business on the date the Holder is deemed to have exercised this Warrant.

         2.8. Vesting. This Warrant may be exercised only to the extent it has
vested in accordance with attached Schedule A.

         2.8 Expiration Date. This Warrant shall expire on the earliest to occur
of the following: (i) September 9, 2006 or (ii) the closing of an acquisition of
the Company by another entity by means of a merger or consolidation.

3. VALID ISSUANCE: TAXES. All shares of Warrant Stock issued upon the exercise
of this Warrant (and shares of Common Stock for issuance on conversion of such
Warrant Stock) shall be validly issued, fully paid and non-assessable, and the
Company shall pay all taxes and other governmental charges that may be imposed
in respect of the issue or delivery thereof. The Company shall not be required
to pay any tax or other charge imposed in connection with any transfer involved
in the issuance of any certificate for shares of Warrant Stock in any name other
than that of the Registered Holder of this Warrant, and in such case the Company
shall not be required to issue or deliver any stock certificate or security
until such tax or other charge has


                                      -4-
<PAGE>   5

been paid, or it has been established to the Company's reasonable satisfaction
that no tax or other charge is due.

4. ADJUSTMENT OF PURCHASE PRICE AND NUMBER OF SHARES. In addition to any
adjustment to the Warrant Stock required by the terms of such Warrant Stock in
the Company's Certificate of Incorporation, the number of shares of Warrant
Stock issuable upon exercise of this Warrant (or any shares of stock or other
securities or property receivable or issuable upon exercise of this Warrant) and
the Purchase Price are subject to adjustment upon occurrence of the following
events:

         4.1. Adjustment for Stock Splits, Stock Subdivisions or Combinations of
Shares. The Purchase Price of this Warrant shall be proportionally decreased and
the number of shares of Warrant Stock issuable upon exercise of this Warrant (or
any shares of stock or other securities at the time issuable upon exercise of
this Warrant) shall be proportionally increased to reflect any stock split or
subdivision of the Company's Warrant Stock. The Purchase Price of this Warrant
shall be proportionally increased and the number of shares of Warrant Stock
issuable upon exercise of this Warrant (or any shares of stock or other
securities at the time issuable upon exercise of this Warrant) shall be
proportionally decreased to reflect any combination of the Company's Warrant
Stock.

         4.2. Adjustment for Dividends or Distributions of Stock or Other
Securities or Property. In case the Company shall make or issue, or shall fix a
record date for the determination of eligible holders entitled to receive, a
dividend or other distribution with respect to the Warrant Stock (or any shares
of stock or other securities at the time issuable upon exercise of the Warrant)
payable in (a) securities of the Company or (b) assets (excluding cash dividends
paid or payable solely out of retained earnings), then, in each such case, the
Holder of this Warrant on exercise hereof at any time after the consummation,
effective date or record date of such dividend or other distribution, shall
receive, in addition to the shares of Warrant Stock (or such other stock or
securities) issuable on such exercise prior to such date, and without the
payment of additional consideration therefor, the securities or such other
assets of the Company to which such Holder would have been entitled upon such
date if such Holder had exercised this Warrant on the date hereof and had
thereafter, during the period from the date hereof to and including the date of
such exercise, retained such shares and/or all other additional stock available
by it as aforesaid during such period giving effect to all adjustments called
for by this Section 4.

         4.3. Reclassification. If the Company, by reclassification of
securities or otherwise, shall change any of the securities as to which purchase
rights under this Warrant exist into the same or a different number of
securities of any other class or classes, this Warrant shall thereafter
represent the right to acquire such number and kind of securities as would have
been issuable as the result of such change with respect to the securities that
were subject to the purchase rights under this Warrant immediately prior to such
reclassification or other change and the Purchase Price therefore shall be
appropriately adjusted, all subject to further adjustment as provided in this
Section 4. No adjustment shall be made pursuant to this Section 4.3 upon any
conversion or redemption of the Warrant Stock which is the subject of Section
4.5.

                                      -5-
<PAGE>   6

         4.4. Adjustment for Capital Reorganization. In case of any capital
reorganization of the capital stock of the Company (other than a combination,
reclassification, exchange or subdivision of shares otherwise provided for
herein), then, as a part of such reorganization, lawful provision shall be made
so that the Holder of this Warrant shall thereafter be entitled to receive upon
exercise of this Warrant, during the period specified herein and upon payment of
the Purchase Price then in effect, the number of shares of stock or other
securities or property of the successor corporation resulting from such
reorganization that a holder of the shares deliverable upon exercise of this
Warrant would have been entitled to receive in such reorganization if this
Warrant had been exercised immediately before such reorganization, all subject
to further adjustment as provided in this Section 4. The foregoing provisions of
this Section 4.4 shall similarly apply to successive reorganizations and to the
stock or securities of any other corporation that are at the time receivable
upon the exercise of this Warrant. If the per-share consideration payable to the
Holder hereof for shares in connection with any such transaction is in a form
other than cash or marketable securities, then the value of such consideration
shall be determined in good faith by the Company's Board of Directors. In all
events, appropriate adjustment (as determined in good faith by the Company's
Board of Directors) shall be made in the application of the provisions of this
Warrant with respect to the rights and interests of the Holder after the
transaction, to the end that the provisions of this Warrant shall be applicable
after that event, as near as reasonably may be, in relation to any shares or
other property deliverable after that event upon exercise of this Warrant.

         4.5. Conversion of Warrant Stock. In case all or any portion of the
authorized and outstanding shares of Warrant Stock of the Company are redeemed
or converted or reclassified into other securities or property pursuant to the
Company's Certificate of Incorporation or otherwise, or the Warrant Stock
otherwise ceases to exist, then, in such case, the Holder of this Warrant, upon
exercise hereof at any time after the date on which the Warrant Stock is so
redeemed or converted, reclassified or ceases to exist (the "Termination Date"),
shall receive, in lieu of the number of shares of Warrant Stock that would have
been issuable upon such exercise immediately prior to the Termination Date, the
securities or property that would have been received if this Warrant had been
exercised in full and the Warrant Stock received thereupon had been
simultaneously converted immediately prior to the Termination Date, all subject
to further adjustment as provided in this Warrant. Additionally, the Purchase
Price shall be immediately adjusted to equal the quotient obtained by dividing
(x) the aggregate Purchase Price of the maximum number of shares of Warrant
Stock for which this Warrant was exercisable immediately prior to the
Termination Date by (y) the number of shares of Warrant Stock of the Company for
which this Warrant is exercisable immediately after the Termination Date, all
subject to further adjustment as provided herein.

5. CERTIFICATE AS TO ADJUSTMENTS. In each case of any adjustment in the Purchase
Price, or number or type of shares issuable upon exercise of this Warrant, the
Chief Financial Officer or Controller of the Company shall compute such
adjustment in accordance with the terms of this Warrant and prepare a
certificate setting forth such adjustment and showing in detail the facts upon
which such adjustment is based, including a statement of the adjusted Purchase
Price. The Company shall promptly send (by facsimile and by either first class
mail, postage prepaid or overnight delivery) a copy of each such certificate to
the Holder.

                                      -6-
<PAGE>   7

6. LOSS OR MUTILATION. Upon receipt of evidence reasonably satisfactory to the
Company of the ownership of and the loss, theft, destruction or mutilation of
this Warrant, and of indemnity reasonably satisfactory to it, and (in the case
of mutilation) upon surrender and cancellation of this Warrant, the Company will
execute and deliver in lieu thereof a new Warrant of like tenor as the lost,
stolen, destroyed or mutilated Warrant.

7. RESERVATION OF WARRANT STOCK. The Company hereby covenants that at all times
there shall be reserved for issuance and delivery upon exercise of this Warrant
such number of shares of Common Stock or other shares of capital stock of the
Company as are from time to time issuable upon exercise of this Warrant and,
from time to time, will take all steps necessary to amend its Certificate of
Incorporation to provide sufficient reserves of shares of Warrant Stock issuable
upon exercise of this Warrant (and shares of its Common Stock for issuance on
conversion of such Warrant Stock). All such shares shall be duly authorized, and
when issued upon such exercise, shall be validly issued, fully paid and
non-assessable, free and clear of all liens, security interests, charges and
other encumbrances or restrictions on sale and free and clear of all preemptive
rights, except encumbrances or restrictions arising under federal or state
securities laws. Issuance of this Warrant shall constitute full authority to the
Company's officers who are charged with the duty of executing stock certificates
to execute and issue the necessary certificates for shares of Warrant Stock (and
shares of Common Stock for issuance on conversion of such Warrant Stock) upon
the exercise of this Warrant.

8. TRANSFER AND EXCHANGE. Upon the closing of the Company's initial public
offering of securities and after Intel Corporation has fully vested all shares
of Warrant Stock pursuant to the conditions described in Attachment A hereto,
subject to the terms and conditions of this Warrant and compliance with all
applicable securities laws, this Warrant and all rights hereunder may be
transferred to any Registered Holder parent, subsidiary or affiliate, in whole
or in part, on the books of the Company maintained for such purpose at the
principal office of the Company referred to above, by the Registered Holder
hereof in person, or by duly authorized attorney, upon surrender of this Warrant
properly endorsed and upon payment of any necessary transfer tax or other
governmental charge imposed upon such transfer. Upon any permitted partial
transfer, the Company will issue and deliver to the Registered Holder a new
Warrant or Warrants with respect to the shares of Warrant Stock not so
transferred. Each taker and holder of this Warrant, by taking or holding the
same, consents and agrees that when this Warrant shall have been so endorsed,
the person in possession of this Warrant may be treated by the Company, and all
other persons dealing with this Warrant, as the absolute owner hereof for any
purpose and as the person entitled to exercise the rights represented hereby,
any notice to the contrary notwithstanding; provided, however that until a
transfer of this Warrant is duly registered on the books of the Company, the
Company may treat the Registered Holder hereof as the owner for all purposes.

         In addition, the Holder agrees that this Warrant and the Warrant Stock
will be deemed Stockholder Shares under the terms of that Second Amended and
Restated Stockholder Agreement dated September 3, 1999 by and among the Company,
the Holder and certain other holders of the Company's securities (the
"Stockholders' Agreement"), and this Warrant and the Warrant Stock will be
subject to all restrictions contained in the Stockholders' Agreement to the
extent such restrictions have not terminated.

                                      -7-
<PAGE>   8

9. RESTRICTIONS ON TRANSFER. The Holder, by acceptance hereof, agrees that,
absent an effective registration statement filed with the SEC under the
Securities Act of 1933, as amended (the "1933 Act"), covering the disposition or
sale of this Warrant or the Warrant Stock issued or issuable upon exercise
hereof or the Common Stock issuable upon conversion thereof, as the case may be,
and registration or qualification under applicable state securities laws, such
Holder will not sell, transfer, pledge, or hypothecate any or all such Warrants
or Warrant Stock, as the case may be, unless (A) the conditions and restriction
of Section 8 above have been met, and (B) either (i) the Company has received an
opinion of counsel, in form and substance reasonably satisfactory to the
Company, to the effect that such registration is not required in connection with
such disposition or (ii) the Company is reasonably satisfied that the sale of
such securities is made pursuant to SEC Rule 144.

10. COMPLIANCE WITH SECURITIES LAWS. By acceptance of this Warrant, the holder
hereby represents, warrants and covenants that any shares of stock purchased
upon exercise of this Warrant or acquired upon conversion thereof shall be
acquired for investment only and not with a view to, or for sale in connection
with, any distribution thereof; that the Holder has had such opportunity as such
Holder has deemed adequate to obtain from representatives of the Company such
information as is necessary to permit the Holder to evaluate the merits and
risks of its investment in the Company; that the Holder is able to bear the
economic risk of holding such shares as may be acquired pursuant to the exercise
of this Warrant for an indefinite period; that the Holder understands that the
shares of stock acquired pursuant to the exercise of this Warrant or acquired
upon conversion thereof will not be registered under the 1933 Act (unless
otherwise required pursuant to exercise by the Holder of the registration
rights, if any, previously granted to the registered Holder) and will be
"restricted securities" within the meaning of Rule 144 under the 1933 Act and
that the exemption from registration under Rule 144 will not be available for at
least one year from the date of exercise of this Warrant, subject to any special
treatment by the SEC for exercise of this Warrant pursuant to Section 2.2, and
even then will not be available unless a public market then exists for the
stock, adequate information concerning the Company is then available to the
public, and other terms and conditions of Rule 144 are complied with; and that
all stock certificates representing shares of stock issued to the Holder upon
exercise of this Warrant or upon conversion of such shares may have affixed
thereto a legend substantially in the following form:

         THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE SECURITIES
         LAWS OF ANY STATE. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON
         TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT
         AS PERMITTED UNDER THE ACT AND THE APPLICABLE STATE SECURITIES LAWS,
         PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. INVESTORS SHOULD BE
         AWARE THAT THEY MAY BE REQUIRED TO BEAR THE FINANCIAL RISKS OF THIS
         INVESTMENT FOR AN INDEFINITE PERIOD OF TIME. THE ISSUER OF THESE
         SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE
         SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR
         RESALE IS IN


                                      -8-
<PAGE>   9



         COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE SECURITIES LAWS.

11. NO RIGHTS OR LIABILITIES AS STOCKHOLDERS. This Warrant shall not entitle the
Holder to any voting rights or other rights as a stockholder of the Company. In
the absence of affirmative action by such Holder to purchase Warrant Stock by
exercise of this Warrant, no provisions of this Warrant, and no enumeration
herein of the rights or privileges of the Holder hereof shall cause such Holder
hereof to be a stockholder of the Company for any purpose.

12. REGISTRATION RIGHTS. All shares of Warrant Stock issuable upon exercise of
this Warrant shall be "Registrable Securities" or such other definition of
securities entitled to registration rights pursuant to the Investor Rights
Agreement dated September 3, 1999, as amended (the "Rights Agreement"), by and
among the Company, the Holder and certain other holders of the Company's
securities.

13. NOTICES. All notices and other communications from the Company to the Holder
shall be given in accordance with the Rights Agreement.

14. HEADINGS. The headings in this Warrant are for purposes of convenience in
reference only, and shall not be deemed to constitute a part hereof.

15. LAW GOVERNING. This Warrant shall be construed and enforced in accordance
with, and governed by, the laws of the State of Delaware.

16. NO IMPAIRMENT. The Company will not, by amendment of its Certificate of
Incorporation or bylaws, or through reorganization, consolidation, merger,
dissolution, issue or sale of securities, sale of assets or any other voluntary
action, avoid or seek to avoid the observance or performance of any of the terms
of this Warrant, but will at all times in good faith assist in the carrying out
of all such terms and in the taking of all such action as may be necessary or
appropriate in order to protect the rights of the Registered Holder of this
Warrant against impairment. Without limiting the generality of the foregoing,
the Company (a) will not increase the par value of any shares of stock issuable
upon the exercise of this Warrant above the amount payable therefor upon such
exercise, and (b) will take all such action as may be necessary or appropriate
in order that the Company may validly and legally issue fully paid and
non-assessable shares of Warrant Stock upon exercise of this Warrant and Common
Stock issued in conversion thereof.

17. NOTICES OF RECORD DATE. In case:

         17.1. the Company shall take a record of the holders of its Common
Stock (or other stock or securities at the time receivable upon the exercise of
this Warrant), for the purpose of entitling them to receive any dividend or
other distribution, or any right to subscribe for or purchase any shares of
stock of any class or any other securities or to receive any other right; or

         17.2. of any consolidation or merger of the Company with or into
another corporation, any capital reorganization of the Company, any
reclassification of the Capital Stock of the


                                      -9-
<PAGE>   10

Company, or any conveyance of all or substantially all of the assets of the
Company to another corporation in which holders of the Company's stock are to
receive stock, securities or property of another corporation; or

         17.3. of any voluntary dissolution, liquidation or winding-up of the
Company; or

         17.4. of any redemption or conversion of all outstanding Common Stock
or Warrant Stock;

then, and in each such case, the Company will mail or cause to be mailed to the
Registered Holder of this Warrant a notice specifying, as the case may be, (i)
the date on which a record is to be taken for the purpose of such dividend,
distribution or right, or (ii) the date on which such reorganization,
reclassification, consolidation, merger, conveyance, dissolution, liquidation,
winding-up, redemption or conversion is to take place, and the time, if any is
to be fixed, as of which the holders of record of Common Stock or (such stock or
securities as at the time are receivable upon the exercise of this Warrant),
shall be entitled to exchange their shares of Common Stock (or such other stock
or securities), for securities or other property deliverable upon such
reorganization, reclassification, consolidation, merger, conveyance,
dissolution, liquidation or winding-up. Such notice shall be delivered at least
thirty (30) days prior to the date therein specified.

18. SEVERABILITY. If any term, provision, covenant or restriction of this
Warrant is held by a court of competent jurisdiction to be invalid, void or
unenforceable, the remainder of the terms, provisions, covenants and
restrictions of this Agreement shall remain in full force and effect and shall
in no way be affected, impaired or invalidated.

19. COUNTERPARTS. For the convenience of the parties, any number of counterparts
of this Warrant may be executed by the parties hereto and each such executed
counterpart shall be, and shall be deemed to be, an original instrument.

20. NO INCONSISTENT AGREEMENTS. The Company will not on or after the date of
this Warrant enter into any agreement with respect to its securities which is
inconsistent with the rights granted to the Holders of this Warrant or otherwise
conflicts with the provisions hereof. The rights granted to the Holders
hereunder do not in any way conflict with and are not inconsistent with the
rights granted to holders of the Company's securities under any other
agreements, except rights that have been waived.

21. SATURDAYS, SUNDAYS AND HOLIDAYS. If the Expiration Date falls on a Saturday,
Sunday or legal holiday, the Expiration Date shall automatically be extended
until 5:00 p.m. the next business day.

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                                      -10-
<PAGE>   11




         IN WITNESS WHEREOF, the parties hereto have executed this Warrant as of
September 9, 1999.

INTEL CORPORATION                               FORMUS COMMUNICATIONS, INC.



By:                                             By:
   ----------------------------                    ---------------------------


-------------------------------                 Bernard G. Dvorak
Printed Name                                    Printed Name


                                                Senior Vice President and Chief
-------------------------------                 --------------------------------
                                                Financial Officer
                                                --------------------------------
Title                                           Title













                      SIGNATURE PAGE TO WARRANT TO PURCHASE
                           SERIES E PREFERRED STOCK OF
                           FORMUS COMMUNICATIONS, INC.



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