Exhibit 10.36.3

                           ERHC INVESTMENT GROUP, LLC
                             c/o Corporate Builders
                       777 South Flagler Drive, Suite 909
                         West Palm Beach, Florida 33401

                              As of April 27, 1999

Environmental Remediation
       Holding Corporation
3-5 Aubry Lane
Oyster Bay, New York 11753
Attention: President

           Re:       Subscription Agreement

Ladies and Gentlemen:

     We refer to the letter if intent, dated as of April 8, 1999 (the "Letter of
Intent"), between ERHC Investment Group, Inc., a corporation organized under the
laws of the  State of  Florida  ("Investment  Group  Inc."),  and  Environmental
Remediation Holding Corporation,  a corporation  organized under the laws of the
State of Colorado (the "Company"),  pursuant to which the Company agreed,  among
other  things:  (i) to issue to  Investment  Group Inc. or its assigns in one or
more  transactions  validly issued,  fully paid, and  nonassessable  shares (the
"Shares")  of common  stock,  par value  $.0001 per share,  of the Company  (the
"Common  Stock")  representing  fifty-one  percent of the issued and outstanding
capital stock of the Company on a fully-diluted basis after giving effect to all
of the transaction  contemplated by the Letter of Intent; and (ii) to enter into
a definitive securities purchase agreement (the "Securities Purchase Agreement")
with  respect to such  issuances  of Common  Stock.  This letter  agreement  (as
amended,   supplemented,   or  otherwise   modified  from  time  to  time,  this
"Agreement),  is intended to set forth the mutual  understanding  and  agreement
between ERHC Investment Group LLC, a limited  liability  company organized under
the  laws  of  the  State  of  Delaware  ("Investor"),  the  assignee  of all of
Investment  Group  Inc.'s  rights  under the Letter of Intent,  and the  Company
regarding  Investor's initial  subscription for a portion of the Shares prior to
the execution and delivery of the Securities  Purchase  Agreement by the parties
thereto.   In   consideration   of   the   respective   agreements,   covenants,
representations,  and  warranties  hereinafter  set  forth  and  other  good and
valuable   consideration,   the  receipt  and   adequacy  of  which  are  hereby
acknowledged,  and  intending to be legally  bound  hereby,  the parties  hereto
hereby agree as follows:

     Investor hereby  irrevocably  subscribes for the portion of the Shares (the
"Initial  Shares")  representing  2.805  percent of the  issued and  outstanding
capital stock of the Company on a fully-diluted basis after giving effect to all
of the transactions contemplated by the Letter of Intent, and Investor shall pay
therefor  in lawful  money of the  United  States of  America  contemporaneously
herewith $165,000 in the aggregate (the "Purchase Price").  Upon payment in full
of the Purchase  Price,  the Company shall issue to Investor the Initial shares,
and  shall  deliver  or cause to be  delivered  to  Investor  a  certificate  or
certificates evidencing such Initial Shares.






     Upon the execution and delivery of the Securities Purchase  Agreement,  the
terms and provisions of the  Securities  Purchase  Agreement  shall apply to the
Initial Shares subscribed for and purchased hereby,  and the other  transactions
contemplated by this Agreement.

     As an  inducement  to the  Company to enter into this  Agreement,  Investor
hereby represents and warrants to the Company that:

          (i)  Investor has duly  executed and  delivered  this  agreement,  and
     (assuming  due  execution  and  delivery  by the  Company)  this  agreement
     constitutes a legal, valid and binding obligation of Investor,  enforceable
     against Investor in accordance with its terms;

          (ii) Investor's execution,  delivery and performance hereof do not and
     will not: (A) violate or conflict with Investor's  certificate of formation
     or  similar  organizational  documents,  or any  law or  any  order,  writ,
     judgment, injunction, decree, stipulation,  determination, or award entered
     by or with any  governmental  authority  and  applicable  to Investor;  (B)
     violate or  infringe  upon any rights of any  person;  or (C)  require  any
     consent, approval, authorization or other order of, action by, filing with,
     or notification to, any governmental authority or any other person; and

          (iii)  Investor  understands  that the  Initial  Shares  have not been
     registered under the Securities Act of 1933, as amended, or the laws of any
     state and may not be sold or transferred, or otherwise disposed of, without
     registration under the Securities Act and applicable state securities laws,
     or pursuant to an exemption therefrom.

     As an  inducement  to  Investor to enter into this  Agreement,  the Company
hereby represents and warrants to Investor as follows:

          (i) The Company has duly executed and delivered  this  agreement,  and
     (assuming  due  execution   and  delivery  by  Investor)   this   agreement
     constitutes  a  legal,   valid  and  binding  obligation  of  the  Company,
     enforceable against the Company in accordance with its terms;

          (ii) The Company's execution,  delivery, and performance hereof do not
     and will not;  (A)  violate or  conflict  with the  Company's  articles  of
     incorporation or by-laws or similar organizational documents, or any law or
     any order, writ, judgment, injunction,  decree, stipulation,  determination
     or award entered by or with any  governmental  authority and  applicable to
     the Company;  (B) violate or infringe upon any rights of any person; or (C)
     require any consent, approval,  authorization or other order of, action by,
     filing with, or notification  to, any  governmental  authority or any other
     person; and

          (iii) Upon issuance, the Initial Shares will be validly issued, fully






     paid, and nonassessable  and will not be subject to any preemptive  rights,
     and  will  represent  not  less  than  2.805  percent  of  the  issued  and
     outstanding  capital  stock of the Company on a  fully-diluted  basis after
     giving  effect to all of the  transactions  contemplated  by the  Letter of
     Intent.

     No amendment  hereof or supplement  or other  modification  hereto,  and no
consent to, or waiver, discharge, or release of, any term or provision or breach
hereof, shall be valid or effective unless such amendment,  supplement, or other
modification,  or such  consent,  waiver,  discharge,  or release is in writing,
expressly refers hereto, and is signed by the party to be bound thereby.

     If any  term or  other  provision  hereof  is  determined  by any  court of
competent  jurisdiction to be invalid,  illegal, or unenforceable in whole or in
part by reason of any applicable law or public  policy,  and such  determination
becomes final and  nonappealable,  such term or other  provision shall remain in
full force and effect to the  fullest  extent  permitted  by law,  and all other
terms and  provisions  hereof  shall  remain in full  force and  affect in their
entirety.

     This  Agreement  shall be  governed  by,  and  construed  and  enforced  in
accordance with, the laws of the State of New York.

     Each party hereto hereby  unconditionally  and irrevocably waives all right
to trial by jury in any action,  suit, or proceeding (whether based on contract,
tort, or otherwise) based upon,  resulting from,  arising out of, or relating to
this Agreement or any transaction or agreement contemplated hereby.

     This  Agreement  may be executed in any number of  counterparts  and by the
different  parties  hereto in separate  counterparts,  each which when  executed
shall be  deemed  to be an  original,  and all of  which  taken  together  shall
constitute one and the same agreement with the same effect as if such signatures
were upon the same instrument.

     Delivery  of an  executed  counterpart  hereof via  telecopier  shall be as
effective as delivery of an manually executed counterpart hereof.

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     Please  evidence your  acknowledgment  of and agreement to the foregoing by
executing and delivering to Levin & Srinivasan LLP,  counsel to the undersigned,
by telecopier at (212) 957-4565 a counterpart hereof.

                                       Very truly yours,

                                        ERHC INVESTMENT GROUP LLC

                                        By: /s/ HOWARD TALKS
                                        ------------------------------
                                              Howard D. Talks
                                                 Member


ACKNOWLEDGED AND AGREED as of April 27, 1999:

ENVIRONMENTAL REMEDIATION
   HOLDING CORPORATION

By: /s/ JAMES A. GRIFFIN, CORP SECRETARY
     -------------------------------------
     Name:    James A. Griffin
     Title:     Corp. Secretary