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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 SCHEDULE 13D/A
                                (Amendment No. 1)

                    Under the Securities Exchange Act of 1934


                               NII HOLDINGS, INC.
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                                (Name of Issuer)


                         COMMON STOCK, $0.001 PAR VALUE
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                         (Title of class of securities)


                                    62913F201
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                                 (CUSIP number)


                               RUSSELL A. THOMPSON
                               MACKAY SHIELDS LLC
                                9 WEST 57 STREET
                            NEW YORK, NEW YORK 10019
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           (Name, address and telephone number of person authorized to
                       receive notices and communications)


                                  JUNE 3, 2003
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             (Date of event which requires filing of this statement)


If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  which is the subject of this  Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box
[_].

NOTE:  Schedules  filed in paper format shall include a signed original and five
copies of the Schedule,  including all exhibits.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purposes of Section 18 of the  Securities  Exchange Act of
1934 (the  "Exchange  Act") or  otherwise  subject  to the  liabilities  of that
section of the Exchange Act but shall be subject to all other  provisions of the
Exchange Act.


                         (Continued on following pages)
                               (Page 1 of 5 pages)
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----------------------------------|            |--------------------------------
CUSIP No.  62913F201              |   13D/A    |
----------------------------------|            |--------------------------------


----------- -------------------------------------------------- -----------------
    1       NAME OF REPORTING PERSON:   MacKay Shields LLC (f/k/a MacKay-Shields
                                        Financial Corporation)

            S.S. OR I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSON:
----------- --------------------------------------------------------------------

    2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:            (a) [_]
                                                                         (b) [_]
----------- --------------------------------------------------------------------

    3       SEC USE ONLY
----------- --------------------------------------------------------------------

    4       SOURCE OF FUNDS:     N/A
----------- --------------------------------------------------------------------

    5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
            TO ITEM 2(d) OR 2(e):                                            [_]
----------- --------------------------------------------------------------------

    6       CITIZENSHIP OR PLACE OF ORGANIZATION:  Delaware
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  NUMBER OF
    SHARES           7     SOLE VOTING POWER:              2,290,894
                     -----------------------------------------------------------
 BENEFICIALLY
   OWNED BY          8     SHARED VOTING POWER:            0
                     -----------------------------------------------------------
     EACH
  REPORTING          9     SOLE DISPOSITIVE POWER:         2,290,894
                     -----------------------------------------------------------

 PERSON WITH         10    SHARED DISPOSITIVE POWER:       0
 -------------------------------------------------------------------------------

    11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY
            REPORTING PERSON:                              2,290,894
 ---------- --------------------------------------------------------------------

    12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
            CERTAIN SHARES:                                                  [_]
 ---------- --------------------------------------------------------------------

    13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):  11.31%
 ---------- --------------------------------------------------------------------

    14      TYPE OF REPORTING PERSON:    IA
 ---------- --------------------------------------------------------------------



                                  Page 2 of 5


                                 SCHEDULE 13D/A


         This  Amendment  No. 1 to  Schedule  13D (the  "Amendment")  amends and
restates  the  Schedule  13D  originally  filed on  November  26, 2002 by MacKay
Shields LLC.

         Item 1.  Security and Issuer.

         This statement  relates to the common stock, par value $0.001 per share
(the "Shares") of NII Holdings, Inc. (the "Company"),  whose principal executive
offices are located at 10700 Parkridge  Boulevard,  Suite 600, Reston,  Virginia
20191.

         Item 2.  Identity and Background.

         The person  filing  this  statement  is MacKay  Shields  LLC, a limited
liability  company  organized  under the laws of Delaware and,  registered as an
investment  adviser  under  the  Investment  Advisers  Act  of  1940  (File  No.
801-19525).  MacKay Shields'  principal address is 9 West 57th Street, New York,
New York  10019.  MacKay  Shields  acts as  investment  manager  for a number of
clients, pension and profit-sharing plans and also to mutual funds.

         MacKay  Shields has never been a party to a civil  proceeding  before a
judicial or administrative  body of competent  jurisdiction as a result of which
it was or is now subject to a judgment,  decree or final order enjoining  future
violations  of, or prohibiting  or mandating  activities  subject to, federal or
state securities laws or finding any violation with respect to such laws.

         Item 3.  Source and Amount of Funds or Other Consideration.

         MacKay Shields  currently  holds (on behalf of those client  accounts),
and has the sole right to vote and direct the disposition of, equity  securities
of the company totaling  2,290,894 shares. All funds used to purchase or acquire
a security  interest in the Company came  directly  from  proceeds of investment
advisory clients.  No single client account holds a beneficial security interest
in the Company equal to or greater than 5%.

         Item 4.  Purpose of Transaction.

         On November 13, 2002, the Plan of Reorganization,  Rights  Subscription
and Backstop Agreement of the Company became effective. Pursuant to the terms of
the Rights  Subscription,  MacKay Shields  received  Shares in the Company.  The
Common Stock held  directly or  indirectly  by MacKay  Shields is being held for
investment  purposes.  On June 3, 2003,  MacKay Shields sold 2,000,000 shares of
Common  Stock.  On June 4, 2003,  MacKay  Shields  sold 50,000  shares of Common
Stock.  MacKay Shields expects to evaluate future potential  transactions in the
Common Stock on a case by case basis.


                                  Page 3 of 5


         Item 5.  Interest in Securities of the Issuer.

         Based upon information  provided by the Company,  there were issued and
outstanding  20,252,599  Shares.  MacKay  Shields (as an  investment  adviser to
several  client  accounts)  is the  holder  of and/or  has the right to  receive
2,290,894  Shares.  Thus for the  purposes  of Reg.  Section  240.13d-3,  MacKay
Shields  is deemed to  beneficially  own  2,290,894  Shares,  or 11.31% of those
deemed issued and outstanding pursuant to Reg. Section 240.13d-3.

         Item 6.  Contracts, Arrangement, Understanding or Relationships
With Respect to Securities of the Issuer.

         Neal P. Goldman and Donald E. Morgan, both employees of MacKay Shields,
are  directors of the Company.  Except as described in this Schedule  13D/A,  no
contracts,  arrangements,  understandings  or similar  relationships  exist with
respect to the  securities of the Company  between MacKay Shields and any person
or entity.

         Item 7.  Material to be Filed as Exhibits.

         None.


                                  Page 4 of 5


                                    SIGNATURE


         After reasonable  inquiry and to the best of my knowledge and belief, I
certify that the information  set forth in this statement is true,  complete and
correct.

Dated:   June 5, 2003



                                            MACKAY SHIELDS LLC



                                                 /S/ RUSSELL A. THOMPSON
                                            ------------------------------------
                                            BY:     Russell A. Thompson
                                            Title:  Chief Compliance Officer



                                  Page 5 of 5