<PAGE>
                                                                     EXHIBIT 4.3



                           CERTIFICATE OF DESIGNATION

                                     of the

                SERIES D EXCHANGEABLE CONVERTIBLE PREFERRED STOCK

                                       of

                              ENERGY PARTNERS, LTD.


                         Pursuant to Section 151 of the
                General Corporation Law of the State of Delaware


                  ENERGY PARTNERS, LTD., a Delaware corporation (the "Company"),
HEREBY CERTIFIES that, pursuant to authority conferred upon the Board of
Directors of the Company by the Restated Certificate of Incorporation of the
Company and in accordance with the provisions of Section 151 of the General
Corporation Law of the State of Delaware, the Board of Directors of the Company
duly adopted a resolution providing for the issuance of a new series of
preferred stock designated as the Series D Exchangeable Convertible Preferred
Stock, which resolution is as follows:

                  RESOLVED, that a series of the Company's preferred stock, par
value $1.00 per share, designated as the Series D Exchangeable Convertible
Preferred Stock be and hereby is created and that the voting powers,
designations, preferences, and relative, participating, optional or other
special rights thereof, and the qualifications, limitations or restrictions
thereof be as follows:

                SERIES D EXCHANGEABLE CONVERTIBLE PREFERRED STOCK


                  SECTION 1. Certain Definitions. The following terms shall have
the following meanings:

                  "Closing Date" means the date of the closing of the first
issuance of the Preferred Stock.

                  "Common Stock" means the Company's Common Stock, $0.01 par
value per share.

                  "Conversion Price" means $8.54, as adjusted from time to time
as set forth in Section 7.2.

                  "Dividend Accrual Date" has the meaning given such term in
Section 3.1(a).

                  "Dividend Payment Date" has the meaning given such term in
Section 3.1(a).

                  "Dividend Period" has the meaning given such term in Section
3.1(a).


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                  "Dividend Rate" means, for any Dividend Period, the rate per
annum set forth opposite the date on which such Dividend Period ends in the
table below.

<Table>
<Caption>

         Dividend Period Ending                          Rate
         ----------------------                          ----
<S>                                                      <C>
          July 15, 2002                                    7%
          January 15, 2003                                 7%
          July 15, 2003                                    7%
          January 15, 2004                                 7%
          July 15, 2004                                    7%
          January 15, 2005                                 7%
          July 15, 2005                                    8%
          January 15, 2006                                 8%
          July 15, 2006                                    9%
          January 15, 2007                                 9%
          July 15, 2007 and thereafter                    10%
</Table>

                  "Dividend Shares" means fully paid and nonassessable shares,
or fractions thereof, of Preferred Stock paid as dividends on Preferred Stock
pursuant to Section 3.2(b).

                  "Exchange Notes" means the subordinated convertible notes of
the Company in the form attached to the Merger Agreement dated as of December
16, 2001 among the Company, Hall-Houston Oil Company and Saints Acquisition
Subsidiary, Inc., issued in exchange for the Preferred Stock in accordance with
this Certificate of Designation, including additional Exchange Notes issued as
interest on outstanding Exchange Notes pursuant to the terms thereof.

                  "Junior Stock" means the Common Stock and any and all classes
or series of capital stock of the Company over which shares of Preferred Stock
have a preference as to distribution of assets on any liquidation of the
Company.

                  "Parity Stock" means any and all other classes or series of
capital stock of the Company ranking as to distribution of assets on any
liquidation of the Company on parity with the Preferred Stock.

                  "Preferred Stock" has the meaning given such term in Section 2
hereof.

                  "Senior Stock" means any and all classes or series of capital
stock of the Company that have a preference over the Preferred Stock as to
distributions of assets on any liquidation of the Company.

                  SECTION 2. Designation, Amount and Ranking of the Preferred
Stock. The designation of the series of preferred stock created by this
resolution shall be "Series D Exchangeable Convertible Preferred Stock" (the
"Preferred Stock"), and the number of shares constituting this series of
Preferred Stock shall be 550,000. Shares of Preferred Stock shall have the
stated value of $100 per share. The Preferred Stock shall in all respects rank
senior in right and priority to the Junior Stock


                                      -2-
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and equal in right and priority to the Parity Stock with respect to the right to
receive dividends or other distributions on liquidation, dissolution or
winding-up of the Company.

                  SECTION 3. Dividends; Restricted Payments.

                  3.1 Dividend Payment.


                  (a) Payment Dates. The holders of the Preferred Stock shall be
entitled to receive, when, as and if declared by the Board of Directors out of
funds legally available for such purpose, dividends payable in accordance with
this Section 3. Dividends on the Preferred Stock shall be cumulative and shall
accrue semiannually in arrears on June 30 and December 31 (each, a "Dividend
Accrual Date") of each year (each six-month period (or such period from the date
of original issue until July 15, 2002) expiring on a Dividend Accrual Date being
referred to herein as a "Dividend Period"). Dividends on any shares of the
Preferred Stock shall be cumulative and shall accrue (whether or not declared
and whether or not there shall be funds legally available for the payment of
dividends) on and from the date of issue of such shares of the Preferred Stock;
provided, however, that dividends in Dividend Shares paid in accordance with
Section 3.2 shall be cumulative and shall accrue on and from the Dividend
Accrual Date in the Dividend Period in which such dividend accrued, regardless
of when such Dividend Shares were actually issued. Dividends payable on the
Preferred Stock for any period less than a full Dividend Period shall be
computed on the basis of the ratio of the number of days in such partial period
to the actual number of days in such full Dividend Period. The date that any
dividend shall be paid pursuant to this Section 3.1 is referred to herein as a
"Dividend Payment Date."

                  (b) Arrearages. Additional dividends shall accrue with respect
to any dividends (including dividends payable pursuant to this sentence) not
paid by the Dividend Accrual Date on which such dividend accrues or in the
manner provided in Section 3.2. Such additional dividends shall accrue whether
or not declared, at the Dividend Rate compounded semiannually, and shall be
payable in the same manner and at such times as provided in Section 3.1 and 3.2
hereof with respect to dividends on each outstanding share of Preferred Stock.

                  (c) Fractional Shares. Each fractional share of Preferred
Stock outstanding or accrued as a Dividend Share shall be entitled to a ratably
proportionate amount of all dividends accruing with respect to each outstanding
share of Preferred Stock pursuant to Section 3.1 hereof, and all dividends with
respect to such fractional shares shall be fully cumulative and shall accrue
(whether or not declared and whether or not there shall be funds legally
available for the payment of dividends) and shall be payable in the same manner
and at such times as provided for in Sections 3.1 and 3.2 hereof with respect to
dividends on each outstanding share of Preferred Stock.

                  3.2 Form of Payment.

                  (a) Cash. Any dividends accrued on the Preferred Stock on or
prior to January 15, 2006 shall when declared be payable in cash at the Dividend
Rate per share of Preferred Stock on the stated value of $100.


                                      -3-
<PAGE>


                  (b) Dividend Shares. Any dividends accrued on the Preferred
Stock after January 15, 2006 and on or before January 14, 2009 shall when
declared be payable, at the option of the Company, either in cash at the
Dividend Rate per share of Preferred Stock on the stated value of $100, or by
issuing Dividend Shares having an aggregate stated value equal to the Dividend
Rate per share of Preferred Stock on the stated value of $100.

                  3.3 Record Date. To the extent permitted by applicable law,
the Board of Directors shall fix a record date for the determination of holders
of the Preferred Stock entitled to receive payment of a dividend declared
thereon, which record date shall be not more than 30 days prior to the
applicable Dividend Payment Date.

                  3.4 Restricted Payments.

                  (a) No dividends shall be declared or paid or set apart for
payment on the Preferred Stock for any period unless full cumulative dividends
have been or contemporaneously are declared and paid or declared and a sum
sufficient for the payment thereof set apart for such payment on the outstanding
Parity Stock for all dividend periods for the Parity Stock terminating on or
prior to the date of payment of such dividends. No full dividends shall be
declared or paid or set aside for payment on any Parity Stock for any period
unless full cumulative dividends have been or contemporaneously are declared and
paid or declared and a sum sufficient for the payment thereof set apart for such
payment on the Preferred Stock for all Dividend Periods terminating on or prior
to the date of payment of such full cumulative dividends. When dividends are not
paid in full, as aforesaid, upon the shares of Preferred Stock and of any other
series of Parity Stock, all dividends declared upon shares of Preferred Stock
and of any other series of Parity Stock shall be declared pro rata so that the
amount of dividends declared per share on the Preferred Stock and such other
series of Parity Stock shall in all cases bear to each other the same ratio that
accrued dividends per share on the shares of the Preferred Stock and such other
series of Parity Stock bear to each other.

                  (b) Unless full cumulative dividends on the Preferred Stock
have been paid prior to or on the date of the declaration of dividends on Junior
Stock, no dividend shall be declared or paid or set aside for payment or other
distribution declared or made upon the Junior Stock.

                  3.5 Failure to Pay Dividends. If and whenever two consecutive
or three total semiannual dividends payable on Preferred Stock have not been
paid in full, the number of directors then constituting the Board of Directors
shall be increased by one and the holders of a majority of the outstanding
shares of Preferred Stock, voting as a single class, shall be entitled to elect
the additional director to serve on the Board of Directors at any annual meeting
of stockholders or special meeting held in place thereof, or at a special
meeting of the holders of the Preferred Stock called as hereinafter provided.
Whenever all arrears in dividends on the Preferred Stock then outstanding shall
have been paid, then the right of the holders of the Preferred Stock to elect
such additional director shall cease (but subject always to the same provisions
for the vesting of such voting rights in the case of any similar future
arrearage in two consecutive or three total semiannual dividends) and the terms
of office of the person elected as director by the holders of the Preferred
Stock shall forthwith terminate and the number of the Board of Directors shall
be reduced accordingly. At any time after such voting


                                      -4-
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power shall have been so vested in the holders of shares of Preferred Stock, the
secretary of the Company may, and upon the written request of any holder of
Preferred Stock (addressed to the secretary at the principal office of the
Company) shall, call a special meeting of the holders of the Preferred Stock of
the Company for the election of the director to be elected by them as herein
provided, such call to be made by notice similar to that provided in the Bylaws
of the Company for a special meeting of the stockholders or as required by law.
If any such special meeting required to be called as above provided shall not be
called by the secretary within 20 days after receipt of any such request, then
any holder of shares of Preferred Stock may call such meeting, upon the notice
above provided, and for that purpose shall have access to the stock books of the
Company. The director elected at any such special meeting shall hold office
until the next annual meeting of the stockholders or special meeting held in
lieu thereof if such office shall not have previously terminated as above
provided. If any vacancy shall occur of the director elected by the holders of
the Preferred Stock, a successor shall be elected by the Board of Directors,
upon the nomination of the holders of the Preferred Stock, to serve until the
next annual meeting of the stockholders or special meeting held in place thereof
if such office shall not have previously terminated as provided above.

                  SECTION 4. Redemption.

                  4.1 Optional Redemption. The Company may, at its option on or
after January 15, 2005, redeem shares of Preferred Stock, in whole but not in
part, at any time, at a redemption price per share equal to $100 plus accrued
and unpaid dividends to the date of redemption.

                  4.2 Redemption Mechanics.

                  (a) Notice. At such time as the Company shall redeem shares of
Preferred Stock, notice of such redemption shall be given by first class mail,
postage prepaid, mailed not less than 15 nor more than 60 days prior to the
redemption date, to each holder of record of the shares to be redeemed, at such
holder's address as the same appears on the stock register of the Company. Each
such notice shall state: (i) the redemption date; (ii) the number of shares of
Preferred Stock to be redeemed; (iii) the redemption price; (iv) the place or
places where certificates for such shares are to be surrendered for payment of
the redemption price; (v) that dividends on the shares to be redeemed will cease
to accrue on such redemption date; and (vi) a description of the conversion
rights of the Preferred Stock.

                  (b) Surrender. Notice having been mailed as aforesaid, from
and after the redemption date (unless default shall be made by the Company in
providing money for the payment of the redemption price) dividends on the shares
of Preferred Stock so called for redemption shall cease to accrue, said shares
shall no longer be deemed to be outstanding, and all rights of the holders
thereof as stockholders of the Company (except the right to receive from the
Company the redemption price plus accrued and unpaid dividends to the redemption
date) shall cease. Upon surrender in accordance with said notice of the
certificates for any shares so redeemed (properly endorsed or assigned for
transfer, if the Board shall so require and the notice shall so state), such
shares shall be redeemed by the Company at the redemption price aforesaid.


                                      -5-
<PAGE>


                  4.3 Status of Preferred Stock After Redemption. Any shares of
Preferred Stock that shall at any time have been redeemed or purchased by the
Company shall, after such redemption, have the status of authorized but unissued
shares of preferred stock, without designation as to series until such shares
are once more designated as part of a particular series by the Board.

                  SECTION 5. Exchange.

                  5.1 Exchange of Preferred Stock for Exchange Notes. The
Company may, at its option, subject to the conditions set forth below, on any
scheduled Dividend Payment Date, exchange the Preferred Stock, in whole but not
in part, together with any accrued and unpaid dividends, for an equal principal
amount of Exchange Notes; provided that on the date of such exchange there is no
contractual impediment to such exchange.

                  5.2 Form of Exchange Notes. Upon any exchange pursuant to
Section 5.1, holders of outstanding shares of Preferred Stock will be entitled
to receive $100 principal amount of Exchange Notes for each $100 stated value of
Preferred Stock and accrued and unpaid dividends thereon held by them. The
Exchange Notes will be issued in registered form, without coupons. Exchange
Notes issued in exchange for Preferred Stock and accrued and unpaid dividends
thereon will be issued in principal amounts of $1,000 and integral multiples
thereof to the extent possible, and will also be issued in principal amounts
less than $1,000 so that each holder of Preferred Stock will receive
certificates representing the entire amount of Exchange Notes to which such
holder's shares of Preferred Stock and accrued and unpaid dividends thereon
entitle such holder; provided that the Company may pay cash in lieu of issuing
an Exchange Note in a principal amount less than $1,000. The person entitled to
receive the Exchange Notes issuable upon such exchange will be treated for all
purposes as the registered holder of such Exchange Notes.

                  5.3 Exchange Mechanics.

                  (a) Notice. At such time as the Company shall exchange shares
of Preferred Stock, notice of such exchange shall be given by first class mail,
postage prepaid, mailed not less than 15 nor more than 60 days prior to the
exchange date, to each holder of record of the shares to be exchanged, at such
holder's address as the same appears on the stock register of the Company. Each
such notice shall state: (i) the exchange date; (ii) the number of shares of
Preferred Stock to be exchanged; (iii) the place or places where certificates
for such shares are to be surrendered for exchange; (iv) that dividends on the
shares to be exchanged will cease to accrue on such exchange date; and (v) a
description of the conversion rights of the Preferred Stock.

                  (b) Surrender. Notice having been mailed as aforesaid, from
and after the exchange date, dividends on the shares of Preferred Stock so
called for exchange shall cease to accrue, said shares shall no longer be deemed
to be outstanding, and all rights of the holders thereof as stockholders of the
Company (except the right to receive from the Company the Exchange Notes) shall
cease. Upon surrender in accordance with said notice of the certificates for any
shares so exchanged (properly endorsed or assigned for transfer, if the Board
shall so require and the notice shall so state), such shares shall be exchanged
by the Company.


                                      -6-
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                  5.4 Status of Preferred Stock After Exchange. Any shares of
Preferred Stock that shall at any time have been exchanged or purchased by the
Company shall, after such exchange, have the status of authorized but unissued
shares of preferred stock, without designation as to series until such shares
are once more designated as part of a particular series by the Board.

                  SECTION 6. Liquidation. In the event of any complete
liquidation, dissolution or winding-up of the Company, whether voluntary or
involuntary, the holders of shares of Preferred Stock shall each be entitled to
receive out of the assets of the Company legally available for distribution to
its stockholders before any distribution shall be made to the holders of Junior
Stock of the Company, for each share of Preferred Stock an amount equal to $100
plus accrued and unpaid dividends to the date of payment. If, upon any
liquidation, dissolution or winding up of the Company, the assets of the
Company, or the proceeds thereof, shall be insufficient to pay in full the
preferential amounts as to which the Preferred Stock and any other series of
Parity Stock would be entitled, then such assets or the proceeds thereof shall
be distributed among holders of Preferred Stock and the holders of any Parity
Stock ratably in accordance with the respective amounts that would be payable on
such shares if all amounts payable thereon were paid in full.

                  SECTION 7. Conversion.

                  7.1 (a) Right of Holder to Convert. Provided that full
cumulative dividends on the Preferred Stock have been or contemporaneously are
declared and paid to the date of conversion, each share of Preferred Stock shall
be convertible at the option of the record holder thereof at any time prior to
the close of business on the date prior to the redemption date for such share,
into the number of shares of fully paid and nonassessable shares of Common Stock
determined by dividing $100 by the Conversion Price in effect at the time of
conversion.

                  (b) Mechanics of Conversion by Holders of Preferred Stock. In
order for any holder of the Preferred Stock to convert the same into Common
Stock, such holder shall present in person or by registered mail, return receipt
requested with postage prepaid thereon, at the principal office of the Company,
the certificate representing such share to the Company by the close of business
on the date prior to the redemption date accompanied by written notice to the
Company that such holder elects to convert all or a specified number of shares
and stating therein its name or the name or names of its nominees in which such
holder wishes the certificate or certificates for Common Stock to be issued. The
Company shall, as soon as practicable thereafter, issue and deliver to such
holder of the Preferred Stock, or to its nominee or nominees, a certificate or
certificates representing the number of shares of Common Stock to which such
holder shall be entitled as aforesaid, and if less than the full number of
shares of the Preferred Stock evidenced by such surrendered certificate or
certificates are being converted, a new certificate or certificates, of like
tenor, for the number of shares of the Preferred Stock evidenced by such
surrendered certificate less the number of such shares being converted.

                  7.2 Adjustments to Conversion Price for Stock Dividends,
Subdivisions and Combinations. In case at any time or from time to time the
Company shall (i) subdivide its outstanding shares of Common Stock into a larger
number of shares of Common Stock (whether by distribution of Common Stock or
otherwise) or (ii) combine its outstanding shares of Common Stock into a


                                      -7-
<PAGE>


smaller number of shares of Common Stock, then the Conversion Price in effect
immediately after the happening of any such event shall be proportionately
decreased, in case of the happening of events described in subparagraph (i)
above, or proportionately increased, in case of the happening of events
described in subparagraph (ii) above. In case at any time or from time to time
the Company shall declare a dividend or make a distribution on the Common Stock
payable in shares of its capital stock (other than shares of Common Stock) or
capital stock of any subsidiary of the Company or any other assets (other than
cash), then the Company shall make appropriate provision to provide the Holder,
upon exercise of this Warrant, of the aggregate number and kind of shares which
the Holder would have received if the Holder had exercised this Warrant
immediately prior to the record date for such dividend or distribution; provided
that no adjustment shall be made if such dividend or distribution is not
actually made.

                  7.3 Merger, Consolidation or Disposition of Assets. In case
the Company shall merge or consolidate into another corporation, or shall sell,
transfer or otherwise dispose of all or substantially all of its property,
assets or business to another corporation, then each holder of a share of the
Preferred Stock shall have the right thereafter to convert such shares only into
the kind and amount of shares of stock and other securities and property
receivable upon or deemed to be held following such merger, consolidation, sale,
transfer or other disposition of assets by a holder of a number of shares of the
Common Stock of the Company into which such shares of Preferred Stock could have
been converted immediately prior to such merger, consolidation, sale, transfer
or other disposition of assets. In case of any such merger, consolidation, sale,
transfer or other disposition of assets, the successor acquiring corporation
shall expressly assume the due and punctual observance and performance of each
and every covenant and condition hereof to be performed and observed by the
Company and all of the obligations and liabilities hereunder, subject to such
modification as shall be necessary to provide for adjustments to the Conversion
Price which shall be as nearly equivalent as practicable to the adjustments
provided for in this Section 7.3. The foregoing provisions of this Section 7.3
shall similarly apply to successive mergers, consolidations, sales, transfers or
other dispositions of assets.

                  7.4 No Impairment. The Company (i) will not permit the par
value of any shares of stock at the time receivable upon the conversion of the
Preferred Stock to exceed the Conversion Price then in effect, (ii) will take
all such action as may be necessary or appropriate in order that the Company may
validly and legally issue fully paid nonassessable shares of Common Stock on the
conversion of the Preferred Stock and (iii) will not issue any Common Stock or
Convertible Securities or take any action which results in any adjustment of the
Conversion Price if the total number of shares of Common Stock issuable after
such issuance or action upon the conversion or redemption of, or payment of all
outstanding dividends on, all of the then outstanding shares of Preferred Stock
will exceed the total number of shares of Common Stock then authorized by the
Company's Certificate of Incorporation and available for the purpose of issue
upon such conversion or redemption or payment of such dividend.

                  7.5 Certificate as to Adjustments. Upon the occurrence of each
adjustment or readjustment of the Conversion Price pursuant to Section 7.2, the
Company at its expense shall promptly compute such adjustment or readjustment in
accordance with the terms hereof and furnish to


                                      -8-
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each holder of the Preferred Stock a certificate setting forth such adjustment
and showing in reasonable detail the facts upon which such adjustment is based.

                  7.6 Notices of Record Date. In the event of any taking by the
Company of a record of the holders of any class of securities for the purpose of
determining the holders thereof who are entitled to receive any dividend or
other distribution, or any right to subscribe for, purchase or otherwise acquire
any shares of stock of any class or any other securities or property, or to
receive any other right, the Company shall use commercially reasonable efforts
to mail to each holder of the Preferred Stock at least ten days prior to the
date specified therein, a notice specifying the date on which any such record is
to be taken for the purpose of such dividend or distribution.

                  7.7 Reservation of Shares. The Company covenants that it will
at all times reserve and keep available, out of its authorized and unissued
Common Stock solely for the purpose of issuance upon conversion of Preferred
Stock as herein provided, free from preemptive rights or any other actual or
contingent purchase rights of persons other than the holders of shares of
Preferred Stock, such number of shares of Common Stock as shall then be issuable
upon the conversion of all outstanding shares of Preferred Stock. The Company
covenants that all shares of Common Stock that shall be so issuable shall upon
issue be duly and validly issued and fully paid and nonassessable.

                  SECTION 8. Voting Rights of Preferred Stock.

                  8.1 General Voting Rights. Holders of Preferred Stock shall
not be entitled to any voting rights except as may be required by Delaware law,
other than the voting rights provided in Section 3.5.

                  8.2 Vote of Series Required. So long as any shares of
Preferred Stock are outstanding, the affirmative vote of the holders of a
majority of the shares of Preferred Stock outstanding at the time shall be
necessary to permit, effect or validate

                  (a) the authorization, creation or issuance, or any increase
         in the authorized or issued amount, of any class or series of Senior
         Stock; and

                  (b) the amendment, alteration or repeal of any of the
         provisions of the Restated Certificate of Incorporation which would
         adversely affect the voting powers, designations, preferences,
         redemption rights, and relative participating, optional or other rights
         and the qualifications, limitations or restrictions of the Preferred
         Stock.

                  8.3 Conflicts. To the extent permitted by applicable law, in
the event of any conflict or inconsistency between (i) any of the provisions of
this Section 8 or any other provision in this Certificate and (ii) the Restated
Certificate of Incorporation or the Bylaws of the Company, as may be amended
from time to time, the terms of this Certificate shall supersede such
conflicting or inconsistent provision and shall control.




                                      -9-
<PAGE>




                  IN WITNESS WHEREOF, ENERGY PARTNERS, LTD. has caused its
corporate seal to be hereunto affixed and this certificate to be executed this
10th day of January, 2002.

                                       ENERGY PARTNERS, LTD.



                                       By:
                                          -------------------------------
                                          Name:  Suzanne Baer
                                          Title: Executive Vice President