<PAGE>
                                                                   Exhibit 4.16a


                                PLEDGE AMENDMENT

To:      HSBC Bank USA (formerly known as
         Marine Midland Bank) as Pledgee under the
         Securities Pledge Agreement described below:

This is to inform you that we have acquired or obtained the following Additional
Shares as defined in the Securities Pledge Agreement dated November 27, 1996,
originally between you and the undersigned, as amended to date:


<TABLE>
<CAPTION>
                                                                                                             Percentage of all
                               Description          Share Nos./                                                   Issued
          Issuer               of Security       Certificate Nos.         Par Value           Amount         Capital of Issuer
          ------               -----------       ----------------         ---------           ------         -----------------
<S>                          <C>                         <C>                <C>              <C>                <C>
  Statia Terminals Canada    1 Common Shares             2                   N/A               N/A                 100%
      Holdings, Inc.

  Statia Terminals Canada      Partnership            1 and 5                N/A              97,000             95.4999%
        Partnership               Units
</TABLE>

and that these Additional Shares are, and to the extent required, are hereby
made, subject to the Pledge as defined in said Securities Pledge Agreement. This
Pledge Amendment forms an integral part of the Securities Pledge Agreement.

Dated:  September 30, 2001



                                       STATIA TERMINALS CANADA, INCORPORATED


                                       By:
                                           -------------------------------------
                                           Name: Paul Crissman
                                           Title: President


                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:






<PAGE>


                     STATIA TERMINALS CANADA HOLDINGS, INC.

                                 ACKNOWLEDGMENT

                  Statia Terminals Canada Holdings, Inc. (the "COMPANY"), hereby
accepts notice of and acknowledges the pledge created by the attached Securities
Pledge Agreement originally between Statia Terminals Canada, Incorporated and
HSBC Bank USA (formerly known as Marine Midland Bank), as Trustee (the
"PLEDGEE") (as amended to date, the "PLEDGE AGREEMENT"), agrees to and
acknowledges the contents of the Pledge Agreement.

Dated:  September 30, 2001

                                       STATIA TERMINALS CANADA HOLDINGS, INC.

                                       By:
                                           -------------------------------------
                                           Name: Paul Crissman
                                           Title: President


                                       By:
                                           -------------------------------------
                                           Name:
                                           Title:









                                      -2-
<PAGE>


                       STATIA TERMINALS CANADA PARTNERSHIP

                                 ACKNOWLEDGMENT

                  Statia Terminals Canada Partnership (the "Partnership") hereby
represented by its managing partner, Statia Terminals Canada, Incorporated (the
"STCI"), accepts notice of and acknowledges the pledge created by the attached
Securities Pledge Agreement by and among Point Tupper Marine Services Limited
and Statia Terminals Canada Holdings, Inc. (collectively, the "Pledgors") and
HSBC Bank USA (formerly known as Marine Midland Bank), as Trustee (the
"PLEDGEE") (the "PLEDGE AGREEMENT"), and each of STCI and the Pledgors agrees to
and acknowledges the contents of the Securities Pledge Agreement, undertakes to
register the pledge of Pledged Interests in the books and records of the
Partnership, including the transfer of voting rights to Pledgee in accordance
with Section 5 and to maintain such registration until Pledgee has instructed in
writing otherwise, and undertakes to Pledgee during the existence of the pledge
created thereby to comply with the provisions of the Pledge Agreement so long as
the pledge is in effect. Each of the undersigned agree that the provisions of
this acknowledgement apply notwithstanding the terms of any restrictions or
conditions contained in the partnership agreement dated September 21, 2001,
among such parties pursuant to which the Partnership was created.

Dated: September 30, 2001



STATIA TERMINALS CANADA                        STATIA TERMINALS CANADA
INCORPORATED, on its own behalf and as         HOLDINGS, INC.
managing partner of STATIA TERMINALS
CANADA PARTNERSHIP.                            By:
                                                  ------------------------------
                                                  Name: Paul Crissman
By:                                               Title: President
   ------------------------------
   Name: Paul Crissman
   Title: President


                                               By:
                                                   -----------------------------
By:                                                Name:
   ------------------------------                  Title:
   Name:
   Title:


POINT TUPPER MARINE SERVICES
LIMITED



By:
   ------------------------------
Title: President