UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No.)*

                          ULTRAPETROL (BAHAMAS) LIMITED
--------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, Par Value $.01 per share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    P94398107
                                    ---------
                                 (CUSIP Number)

                                 April 20, 2007
                                 --------------
                      (Date of Event which Requires Filing
                               of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

             [ ]      Rule 13d-1(b)
             [X]      Rule 13d-1(c)
             [ ]      Rule 13d-1(d)



*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

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


                                  Page 1 of 10





-------------------                                           ------------------
CUSIP No. P94398107                   13G                     Page 2 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Advisors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       1,571,400 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            1,571,400 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,571,400 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           4.7% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 2 of 10





-------------------                                           ------------------
CUSIP No. P94398107                   13G                     Page 3 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       1,571,400 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            1,571,400 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,571,400 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           4.7% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 3 of 10





-------------------                                           ------------------
CUSIP No. P94398107                   13G                     Page 4 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Sigma Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       775,000 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            775,000 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           775,000 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           2.3% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 4 of 10





-------------------                                           ------------------
CUSIP No. P94398107                   13G                     Page 5 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Steven A. Cohen
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       2,346,400 (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            2,346,400 (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           2,346,400 (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           7.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           IN
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 5 of 10





Item 1(a)           Name of Issuer:
                    --------------

                    Ultrapetrol (Bahamas) Limited

Item 1(b)           Address of Issuer's Principal Executive Offices:
                    -----------------------------------------------

                    Ocean Centre, Montagu Foreshore, East Bay St.,
                    Nassau, Bahamas
                    P.O. Box SS-19084

Items 2(a)          Name of Person Filing:
                    ---------------------

                    This statement is filed by: (i) S.A.C. Capital Advisors,
                    LLC, ("SAC Capital Advisors") with respect to shares of
                    common stock, par value $.01 per share ("Shares"), of the
                    Issuer beneficially owned by S.A.C. Capital Associates, LLC
                    ("SAC Capital Associates"); (ii) S.A.C. Capital Management,
                    LLC, ("SAC Capital Management") with respect to Shares
                    beneficially owned by SAC Capital Associates; (iii) Sigma
                    Capital Management, LLC ("Sigma Management") with respect to
                    Shares beneficially owned by Sigma Capital Associates, LLC
                    ("Sigma Capital Associates"); and (iv) Steven A. Cohen with
                    respect to Shares beneficially owned by SAC Capital
                    Advisors, SAC Capital Management, SAC Capital Associates,
                    Sigma Management and Sigma Capital Associates.

                    SAC Capital Advisors, SAC Capital Management, Sigma
                    Management and Steven A. Cohen have entered into a Joint
                    Filing Agreement, a copy of which is filed with this
                    Schedule 13G as Exhibit 99.1, pursuant to which they have
                    agreed to file this Schedule 13G jointly in accordance with
                    the provisions of Rule 13d-1(k) of the Securities Exchange
                    Act of 1934, as amended.

Item 2(b)           Address of Principal Business Office:
                    ------------------------------------

                    The address of the principal business office of (i) SAC
                    Capital Advisors and Mr. Cohen is 72 Cummings Point Road,
                    Stamford, Connecticut 06902 and (ii) SAC Capital Management
                    and Sigma Management is 540 Madison Avenue, New York, New
                    York 10022.

Item 2(c)           Citizenship:
                    -----------

                    SAC Capital Advisors, SAC Capital Management and Sigma
                    Management are Delaware limited liability companies. Mr.
                    Cohen is a United States citizen.


                                  Page 6 of 10





Item 2(d)           Title of Class of Securities:
                    ----------------------------

                    Common Stock, par value $.01 per share

Item 2(e)           CUSIP Number:
                    ------------

                    P94398107

Item 3              Not Applicable

Item 4              Ownership:
                    ---------

                    The percentages used herein are calculated based upon the
                    Shares issued and outstanding as of April 19, 2007 as
                    reported on the Issuer's Prospectus report on Form 424B1
                    filed with the Securities and Exchange Commission by the
                    Issuer dated April 19, 2007.

                    As of the close of business on April 20, 2007:

                    1. S.A.C. Capital Advisors, LLC
                    (a) Amount beneficially owned: 1,571,400
                    (b) Percent of class: 4.7%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 1,571,400
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    1,571,400

                    2. S.A.C. Capital Management, LLC
                    (a) Amount beneficially owned: 1,571,400
                    (b) Percent of class: 4.7%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 1,571,400
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    1,571,400

                    3. Sigma Capital Management, LLC
                    (a) Amount beneficially owned: 775,000
                    (b) Percent of class: 2.3%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 775,000
                    (iii) Sole power to dispose or direct the disposition: -0-


                                  Page 7 of 10





                    (iv) Shared power to dispose or direct the disposition:
                    775,000

                    4. Steven A. Cohen
                    (a) Amount beneficially owned: 2,346,400
                    (b) Percent of class: 7.0%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 2,346,400
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    2,346,400

                    SAC Capital Advisors, SAC Capital Management, Sigma
                    Management and Mr. Cohen own directly no Shares. Pursuant to
                    investment agreements, each of SAC Capital Advisors and SAC
                    Capital Management share all investment and voting power
                    with respect to the securities held by SAC Capital
                    Associates. Pursuant to an investment management agreement,
                    Sigma Management maintains investment and voting power with
                    respect to the securities held by Sigma Capital Associates.
                    Mr. Cohen controls each of SAC Capital Advisors, SAC Capital
                    Management and Sigma Management. By reason of the provisions
                    of Rule 13d-3 of the Securities Exchange Act of 1934, as
                    amended, each of (i) SAC Capital Advisors, SAC Capital
                    Management and Mr. Cohen may be deemed to own beneficially
                    1,571,400 Shares (constituting approximately 4.7% of the
                    Shares outstanding) and (ii) Sigma Management and Mr. Cohen
                    may be deemed to own beneficially 775,000 Shares
                    (constituting approximately 2.3% of the Shares outstanding).
                    Each of SAC Capital Advisors, SAC Capital Management, Sigma
                    Management and Mr. Cohen disclaim beneficial ownership of
                    any of the securities covered by this statement.

Item 5              Ownership of Five Percent or Less of a Class:
                    --------------------------------------------

                    If this statement is being filed to report the fact that as
                    of the date hereof the reporting person has ceased to be the
                    beneficial owner of more than five percent of the class of
                    securities, check the following. [ ]

Item 6              Ownership of More than Five Percent on Behalf of Another
                    --------------------------------------------------------
                    Person:
                    ------

                    Not Applicable


                                  Page 8 of 10





Item 7              Identification and Classification of the
                    ----------------------------------------
                    Subsidiary Which Acquired the Security Being
                    --------------------------------------------
                    Reported on By the Parent Holding Company:
                    -----------------------------------------

                    Not Applicable

Item 8              Identification and Classification of Members
                    --------------------------------------------
                    of the Group:
                    ------------

                    Not Applicable

Item 9              Notice of Dissolution of Group:
                    ------------------------------

                    Not Applicable

Item 10             Certification:
                    -------------

     By signing below the signatory certifies that, to the best of his knowledge
and belief, the securities referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing the control of
the issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose or
effect.


                                  Page 9 of 10





                                    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:  April 30, 2007


S.A.C. CAPITAL ADVISORS, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


S.A.C. CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


SIGMA CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


STEVEN A. COHEN


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


                                 Page 10 of 10