NOBLE AFFILIATES INC
S-3, 1996-10-17
CRUDE PETROLEUM & NATURAL GAS
Previous: NATIONSBANK CORP, 424B2, 1996-10-17
Next: OHIO CASUALTY CORP, 13F-E, 1996-10-17



<PAGE>   1
 
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON OCTOBER 17, 1996
 
                                                      REGISTRATION NO. 333-
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ---------------------
                                    FORM S-3
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933
                             ---------------------
                             NOBLE AFFILIATES, INC.
             (Exact name of registrant as specified in its charter)
 
<TABLE>
<S>                                                <C>
                     DELAWARE                                          73-0785597
          (State or other jurisdiction of                           (I.R.S. Employer
          incorporation or organization)                           Identification No.)
</TABLE>
 
                               110 WEST BROADWAY
                            ARDMORE, OKLAHOMA 73401
                                 (405) 223-4110
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                             ---------------------
                                 ROBERT KELLEY
          CHAIRMAN OF THE BOARD, PRESIDENT AND CHIEF EXECUTIVE OFFICER
                             NOBLE AFFILIATES, INC.
                               110 WEST BROADWAY
                            ARDMORE, OKLAHOMA 73401
                                 (405) 223-4110
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                             ---------------------
                                   Copies to:
 
<TABLE>
<S>                                                <C>
                ROBERT D. CAMPBELL                                 EDWIN D. WILLIAMSON
                MICHAEL L. BENGTSON                                SULLIVAN & CROMWELL
              THOMPSON & KNIGHT, P.C.                         1701 PENNSYLVANIA AVE., N.W.
          1700 PACIFIC AVENUE, SUITE 3300                      WASHINGTON, D.C. 20006-5805
                DALLAS, TEXAS 75201                                  (202) 956-7500
                  (214) 969-1700
</TABLE>
 
                             ---------------------
     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after this registration statement becomes effective.
 
     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box.  / /
 
     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box.  /X/
 
     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering.  / /
 
     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.  / /
 
     If delivery of the Prospectus is expected to be made pursuant to Rule 434,
please check the following box.  / /
                                   -------------------
                              CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
============================================================================================================
                                                         PROPOSED MAXIMUM     PROPOSED
TITLE OF EACH CLASS OF                     AMOUNT TO BE   OFFERING PRICE  MAXIMUM AGGREGATE    AMOUNT OF
SECURITIES TO BE REGISTERED                 REGISTERED      PER UNIT(1)   OFFERING PRICE(1) REGISTRATION FEE
- ------------------------------------------------------------------------------------------------------------
<S>                                        <C>                <C>           <C>                <C>
 
Common Stock, par value $3.33 1/3 per
  share..................................  6,275,579 shs.      $44.00       $276,125,476       $83,675
============================================================================================================
</TABLE>
 
(1) Estimated pursuant to Rule 457(c) solely for the purpose of calculating the
    registration fee based on the average of the high and low sales prices of
    the Common Stock as reported on the New York Stock Exchange on October 11,
    1996.
                             ---------------------
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>   2
 
PROSPECTUS
 
                                6,275,579 SHARES
 
                             NOBLE AFFILIATES, INC.
                                  COMMON STOCK
                             ---------------------
 
     This Prospectus covers the issuance of a maximum of 6,275,579 shares of
Common Stock, par value $3.33 1/3 per share ("Common Stock"), of Noble
Affiliates, Inc. (the "Company") under the standby arrangements described herein
under "Standby Arrangements" and the reoffering of any Common Stock issued upon
conversion of the outstanding 4 1/4% Convertible Subordinated Notes due November
1, 2003 (the "Notes") of the Company into Common Stock by UBS Securities LLC
(the "Purchaser") or pursuant to such standby arrangements.
 
     The Company has called all of the Notes for redemption on November 1, 1996
(the "Redemption Date") at a redemption price (the "Redemption Price") of
102.975% of the principal amount thereof, or $1,029.75 per $1,000 principal
amount of Notes. The installment of interest due and payable on November 1, 1996
(a regular interest payment date) on the Notes will be paid to the holders (the
"Record Date Holders") of the Notes of record at the close of business on
October 15, 1996, which was the regular record date for such interest payment
date. This installment of interest will be payable with respect to Notes of the
Record Date Holders notwithstanding any conversion or the redemption of any such
Notes. Subject to the immediately preceding sentence, no payment or adjustment
will be made upon any conversion on account of any interest accrued on the Notes
surrendered for conversion or on account of any dividends on the shares of
Common Stock issuable upon conversion of the Notes.
 
     The Notes are convertible into shares of Common Stock at the conversion
price of $36.65 of principal amount of Notes per share of Common Stock or
approximately 27.285 shares of Common Stock for each $1,000 principal amount of
Notes at any time prior to 5:00 P.M., New York City time, on the Redemption
Date. Cash will be paid in lieu of any fractional shares of Common Stock
issuable upon conversion of the Notes. Any Notes not duly surrendered for
conversion prior to the expiration of convertibility on the Redemption Date
shall be redeemed on the Redemption Date. No interest will accrue on the Notes
on and after the Redemption Date.
 
     The Common Stock is listed on the New York Stock Exchange under the symbol
"NBL." On October 16, 1996, the reported last sale price of the Common Stock on
the New York Stock Exchange was $43 3/8 per share.
 
     A holder of Notes who converted $1,000 principal amount of Notes on October
16, 1996 would have received Common Stock (and cash in lieu of any fractional
share) having a market value of $1,183.49, based on the reported last sale price
of the Common Stock on the New York Stock Exchange on that date. As long as the
market price of the Common Stock (after giving effect to any applicable sales
costs or transfer taxes, if any) is greater than $37.74 per share, a holder of
Notes who elects to convert will receive upon conversion, Common Stock (and cash
in lieu of any fractional share) having a current market value greater than the
cash Redemption Price such holder would otherwise be entitled to receive upon
the redemption of the Notes. Holders should note, however, that the price of the
Common Stock received upon conversion will fluctuate in the market, and holders
may expect to incur various expenses of sale if and when such Common Stock is
sold. See "Price Range of Common Stock and Dividends."
 
     The Company has made arrangements with the Purchaser pursuant to which the
Purchaser has agreed, subject to certain conditions, to purchase from the
Company a number of authorized but unissued shares of Common Stock equal to the
total number of shares of Common Stock that would have been issued upon
conversion of any Notes that are not duly surrendered for conversion prior to
the expiration of convertibility on the Redemption Date. The purchase price for
such Common Stock will be $37.74 per share. The Purchaser may also purchase
Notes in the open market or otherwise prior to expiration of convertibility on
the Redemption Date. See "Standby Arrangements" for a description of the
Purchaser's compensation and indemnification arrangements with the Company.
 
     Prior to, on or after the Redemption Date, the Purchaser may offer shares
of Common Stock, including shares acquired through the purchase and conversion
of Notes, directly to the public, at prices set from time to time by it. It is
intended that an offering price set on any calendar day will not be increased
more than once during such day and will not exceed the greater of the last sale
price and the current asked price of the Common Stock on the New York Stock
Exchange, plus applicable dealers' concessions. The Purchaser may thus realize
profits or losses independent of the compensation referred to under "Standby
Arrangements." The Purchaser may also make sales to dealers at prices which
represent concessions from the prices at which such shares are then being
offered to the public. The amounts of such concessions are to be determined from
time to time by the Purchaser. Any Common Stock so offered is offered subject to
prior sale, when, as and if received by the Purchaser, and subject to its right
to reject orders in whole or in part. This Prospectus does not constitute an
offer to sell any securities other than the Common Stock offered by the
Purchaser.
                             ---------------------
 
 THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
      EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
          SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES
           COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS
             PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
                              CRIMINAL OFFENSE.
                             ---------------------
 
                                 UBS SECURITIES
 
October 17, 1996
<PAGE>   3
 
     IN CONNECTION WITH THIS OFFERING, THE PURCHASER MAY OVER-ALLOT OR EFFECT
TRANSACTIONS WHICH STABILIZE OR MAINTAIN THE MARKET PRICE OF THE COMMON STOCK OR
THE NOTES AT LEVELS ABOVE THOSE WHICH MIGHT OTHERWISE PREVAIL IN THE OPEN
MARKET. SUCH TRANSACTIONS MAY BE EFFECTED ON THE NEW YORK STOCK EXCHANGE, IN THE
OVER-THE-COUNTER MARKET OR OTHERWISE. SUCH STABILIZING, IF COMMENCED, MAY BE
DISCONTINUED AT ANY TIME.
 
                DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS
 
     This Prospectus includes "forward-looking statements" within the meaning of
Section 27A of the Securities Act of 1933, as amended (the "Securities Act"),
and Section 21E of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"). All statements other than statements of historical facts
included in this Prospectus and the documents incorporated herein by reference,
including without limitation, statements under "The Company -- Business
Strategy," "-- Exploration and Development," "-- Properties -- Reserves" and
"-- Hedging Arrangements," regarding the Company's estimates of oil and gas
reserves and the future net cash flows attributable thereto, anticipated capital
expenditures, business strategy, plans and objectives of management of the
Company for future operations and industry conditions, are forward-looking
statements. Although the Company believes that the expectations reflected in
such forward-looking statements are reasonable, it can give no assurance that
such expectations will prove to have been correct. Important factors that could
cause actual results to differ materially from the Company's expectations
("Cautionary Statements") include without limitation future production levels,
future prices and demand for oil and gas, results of future exploration and
development activities, future operating and development costs, the effect of
existing and future laws and governmental regulations (including those
pertaining to the environment) and the political and economic climate of the
United States and the foreign countries in which the Company operates from time
to time, as discussed in this Prospectus and the other documents of the Company
filed with the Securities and Exchange Commission (the "Commission"). All
subsequent written and oral forward-looking statements attributable to the
Company or persons acting on its behalf are expressly qualified in their
entirety by the Cautionary Statements.
 
                            OIL AND GAS TERMINOLOGY
 
     Quantities of oil, condensate and natural gas liquids are expressed in this
Prospectus in barrels ("bbls"), thousands of barrels ("Mbbls") or millions of
barrels ("MMbbls"), and quantities of natural gas are expressed in thousands of
cubic feet ("Mcf"), millions of cubic feet ("MMcf") or billions of cubic feet
("Bcf"). As used herein, "Mcfe" means thousands of cubic feet of gas equivalent,
"MMcfe" means millions of cubic feet of gas equivalent and "Bcfe" means billions
of cubic feet of gas equivalent; and "MMBTU" means one million British Thermal
Units. Oil, condensate and natural gas liquids are converted to gas equivalents
using the ratio of six Mcf of natural gas to one barrel of oil, condensate or
natural gas liquids. A "gross" acre or well is an acre or well in which a
working interest is owned, and a "net" acre or well is deemed to exist when the
sum of fractional ownership interests in gross acres or wells equals one.
"Undeveloped acreage" means lease acres on which wells have not been drilled or
completed to a point that would permit production of commercial quantities of
oil or gas regardless of whether such acreage contains proved reserves,
including lease acres (held by production under terms of a lease) that are not
within the spacing unit containing, or acreage assigned to, the productive well
so holding the lease.
 
                                        2
<PAGE>   4
 
                             AVAILABLE INFORMATION
 
     The Company is subject to the informational requirements of the Exchange
Act and in accordance therewith files reports, proxy statements and other
information with the Commission. Such reports, proxy statements and other
information filed by the Company can be inspected and copied at the public
reference facilities maintained by the Commission at Judiciary Plaza, 450 Fifth
Street N.W., Room 1024, Washington, D.C. 20549, and at the Commission's regional
offices at Northwestern Atrium Center, 500 West Madison Street, Suite 1400,
Chicago, Illinois 60661-2511, and Seven World Trade Center, New York, New York
10048. Copies of such material can also be obtained from the Commission at
prescribed rates through its Public Reference Section at 450 Fifth Street N.W.,
Room 1024, Washington, D.C. 20549. In addition, similar information concerning
the Company can be inspected and copied at the New York Stock Exchange, 20 Broad
Street, New York, NY 10005.
 
     The Company has filed with the Commission a Registration Statement on Form
S-3 under the Securities Act with respect to the Common Stock offered hereby
(including all amendments or supplements thereto, the "Registration Statement").
This Prospectus, which forms a part of the Registration Statement, does not
contain all the information set forth in the Registration Statement, certain
parts of which have been omitted in accordance with the rules and regulations of
the Commission. Statements contained herein concerning the provisions of certain
documents are not necessarily complete and, in each instance, reference is made
to the copy of such document filed as an exhibit to the Registration Statement
or otherwise filed with the Commission. Each such statement is qualified in its
entirety by such reference.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
     The following documents filed by the Company with the Commission (File No.
0-7062) pursuant to the Exchange Act are incorporated herein by reference: (i)
Annual Report on Form 10-K for the year ended December 31, 1995, as amended by
Form 10-K/A (No. 1) dated June 27, 1996; (ii) Quarterly Reports on Form 10-Q for
the quarters ended March 31, 1996 and June 30, 1996; and (iii) Current Report on
Form 8-K (Date of Event: July 31, 1996) dated August 13, 1996, as amended by
Form 8-K/A (No. 1) dated September 27, 1996. All other documents filed by the
Company pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act
subsequent to the date of this Prospectus and prior to the termination of the
offering of the Common Stock shall be deemed to be incorporated by reference in
this Prospectus from the date of filing thereof.
 
     Any statement contained herein or in a document or information incorporated
or deemed to be incorporated by reference herein shall be deemed to be modified
or superseded to the extent that a statement contained herein or in any
subsequently filed document which also is, or is deemed to be, incorporated by
reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Prospectus.
 
     The Company will provide without charge to each person to whom this
Prospectus is delivered, upon the written or oral request of any such person, a
copy of any or all of the foregoing documents or information that has been
incorporated by reference in this Prospectus, other than exhibits to such
documents (unless such exhibits are specifically incorporated by reference into
such documents). Requests should be directed to William D. Dickson, Vice
President -- Finance and Treasurer, Noble Affiliates, Inc., P.O. Box 1967,
Ardmore, Oklahoma 73402, (405) 223-4110.
 
                                        3
<PAGE>   5
 
                                  THE COMPANY
 
GENERAL
 
     The Company is an independent energy company engaged, through its
subsidiaries, in the exploration, production and marketing of crude oil and
natural gas. It conducts operations throughout the major basins of the United
States as well as in selected international areas. The Company is one of the
largest independent oil and gas companies in the United States.
 
     The Company, incorporated in Delaware in 1969, and its predecessors have
been engaged in oil and gas exploration and production since 1932. Its principal
executive offices are located at 110 West Broadway, Ardmore, Oklahoma 73401, and
its telephone number is (405) 223-4110. Unless otherwise indicated or the
context otherwise requires, the "Company" refers to Noble Affiliates, Inc. and
its subsidiaries (including EDC) and predecessors and "EDC" refers to Energy
Development Corporation and its subsidiaries (see "-- Business Strategy -- EDC
Acquisition").
 
BUSINESS STRATEGY
 
     The Company's principal business strategy is to increase reserves,
production and cash flow through a balanced program of exploratory and
development drilling, supplemented by strategic acquisitions. During the
three-year period ended December 31, 1995, the Company replaced approximately
273 percent of its production at an average cost of $0.86 per Mcfe. From January
1, 1993 through December 31, 1995, the Company (not including EDC) increased its
proved reserves from 372.2 Bcf of gas and 47.4 MMbbls of oil to 850.3 Bcf of gas
and 84.0 MMbbls of oil. Additionally, the Company (not including EDC) increased
its production from 75.1 Bcf of gas and 7.4 MMbbls of oil in 1993 to 97.0 Bcf of
gas and 9.6 MMbbls of oil in 1995.
 
     The Company seeks to achieve operating and technical efficiencies by
focusing its exploration and development drilling efforts in areas in which the
Company has a concentration of existing producing properties, the most important
of which is its portfolio of properties in the Gulf of Mexico. The Company seeks
to retain the largest available interest consistent with its analysis of the
risks and potential returns of a prospect and to serve as operator whenever
appropriate. Typically, the Company finances its exploration and development
drilling with internally generated funds.
 
     The Company seeks to supplement its exploration and development drilling
activities with acquisitions of producing and non-producing properties. The
Company attempts to acquire properties that complement its existing operations,
thereby allowing the Company to use its engineering knowledge and expertise in
the area, and in many cases its existing facilities, to find, develop and
produce reserves in a cost-effective manner. In addition, the Company actively
seeks to increase its average working interest per well by purchasing additional
interests in existing properties and divesting non-strategic or economically
marginal wells or wells in which it has a small interest.
 
  EDC Acquisition
 
     Pursuant to its stated business strategy, on July 31, 1996, the Company
purchased all of the outstanding common stock of Energy Development Corporation,
a wholly owned indirect subsidiary of Public Service Enterprise Group
Incorporated (the "EDC Acquisition"), for approximately $768 million in cash.
EDC's major properties are located domestically in the Gulf of Mexico and
onshore Louisiana and Texas, and internationally in Argentina and the United
Kingdom sector of the North Sea.
 
     As of December 31, 1995, EDC's estimated proved reserves were approximately
460.9 Bcf of gas and 37.5 MMbbls of oil, as evaluated by Samedan Oil Corporation
("Samedan"), a wholly owned subsidiary of the Company. Approximately 67 percent
of such reserves were natural gas and 75 percent of such reserves were located
in the United States. EDC's average daily production in 1995 and the six months
ended June 30, 1996 was approximately 205 MMcf and 205 MMcf of gas and 11,000
bbls and 12,000 bbls of oil, respectively. Approximately 87 percent of such
production of EDC for the six months ended June 30, 1996 was located in
 
                                        4
<PAGE>   6
 
the United States. As of December 31, 1995, EDC held 483,344 net domestic
undeveloped leasehold acres, and royalty, overriding royalty and other mineral
interests in 37,663 net acres.
 
     On a pro forma basis giving effect to the EDC Acquisition, as of December
31, 1995, the Company's estimated proved reserves were approximately 2,040.2
Bcfe. Natural gas accounted for approximately 64 percent of such proved
reserves. Approximately 86 percent of such proved reserves were located in the
United States, most notably in the Gulf of Mexico, with the balance located in
Argentina, the North Sea, Equatorial Guinea and Canada. The Company's average
daily production in 1995 and the six months ended June 30, 1996, pro forma for
the EDC Acquisition, was approximately 696.9 MMcfe and 811.9 MMcfe,
respectively. Approximately 91 percent of such production for the six months
ended June 30, 1996 was located in the United States.
 
     The Company believes that the EDC Acquisition achieved several of its
strategic objectives. First, it materially enhanced and leveraged the Company's
significant position in the Gulf of Mexico where the Company's proved reserves
as of December 31, 1995 (pro forma for the EDC Acquisition) increased 46 percent
to approximately 993.9 Bcfe. Second, it furthers the Company's goals of owning
large working interests in oil and gas properties and operating such properties
whenever appropriate. The Company believes that it can capitalize on its
capabilities as a low-cost operator and realize cost savings, particularly in
the Gulf of Mexico, where it already has extensive operations in place. Third,
the longer-lived reserves of certain of EDC's domestic onshore and international
properties provide an attractive balance to the Company's shorter-lived fields
in the Gulf of Mexico. Fourth, the acquisition of international reserves in
Argentina and the United Kingdom sector of the North Sea adds geographic
diversity to the Company's portfolio of oil and gas properties consistent with
its traditional risk profile.
 
     In connection with the EDC Acquisition, the Company entered into a new $800
million bank credit facility pursuant to a credit agreement (the "Credit
Agreement") dated as of July 31, 1996. Borrowings of $800 million under the
Credit Agreement were used to fund the purchase price for EDC and, together with
funds on hand, to repay $48 million of outstanding indebtedness under the
Company's then existing bank credit agreement, which was cancelled in connection
with the repayment thereunder. The Credit Agreement generally permits the
Company to prepay at its option, in whole or in part and without premium or
penalty, the indebtedness under the Credit Agreement. The Company therefore has
the ability to consider the refinancing of part or all of the indebtedness
outstanding under the Credit Agreement from time to time in the public or
private financial markets on such terms as it considers satisfactory.
 
EXPLORATION AND DEVELOPMENT
 
     The Company has numerous drilling and development opportunities throughout
its portfolio, the most important of which are on its extensive Gulf of Mexico
properties. The Company's capital expenditures in the six months ended June 30,
1996 for exploration and development drilling, not including any such drilling
associated with properties acquired through the EDC Acquisition, were
approximately $129 million, of which approximately 70 percent was spent in the
Gulf of Mexico. The Company currently estimates that its capital expenditures
for exploration and development drilling for the last six months of 1996,
including any such drilling associated with properties acquired through the EDC
Acquisition, will be approximately $100 million, of which approximately 70
percent is scheduled to be spent in the Gulf of Mexico.
 
                                        5
<PAGE>   7
 
PROPERTIES
 
  Reserves
 
     The following table sets forth information as to estimated net proved and
proved developed reserves as of December 31, 1995 for (i) the Company, (ii) EDC
and (iii) the Company on a pro forma combined basis, assuming the EDC
Acquisition occurred on December 31, 1995. For additional information about the
Company's reserves and the standardized measure of discounted future net cash
flows attributable thereto (not including EDC), see Note 10 of the Notes to
Consolidated Financial Statements incorporated in this Prospectus by reference
to the Company's Form 10-K for the year ended December 31, 1995, as amended.
 
                       TOTAL PROVED AND PROVED DEVELOPED
                        RESERVES AS OF DECEMBER 31, 1995
 
<TABLE>
<CAPTION>
                                            COMPANY              EDC(1)          PRO FORMA COMBINED
                                       -----------------    -----------------    -------------------
                                        GAS       OIL        GAS       OIL         GAS        OIL
                                       (BCF)    (MMBBLS)    (BCF)    (MMBBLS)     (BCF)     (MMBBLS)
                                       -----    --------    -----    --------    -------    --------
<S>                                    <C>      <C>         <C>      <C>         <C>        <C>
Total Proved Reserves:
  Domestic:
     Offshore Gulf of Mexico.........  513.3      27.9      241.2      12.0        754.5       39.9
     Onshore.........................  305.0      43.0      171.8       4.7        476.8       47.7
                                       -----      ----      -----      ----      -------      -----
                                       818.3      70.9      413.0      16.7      1,231.3       87.6
  International......................   32.0      13.1       47.9      20.8         79.9       33.9
                                       -----      ----      -----      ----      -------      -----
                                       850.3      84.0      460.9      37.5      1,311.2      121.5
                                       =====      ====      =====      ====      =======      =====
Total Proved Developed Reserves......  782.8      79.0      409.8      29.0      1,192.6      108.0
                                       =====      ====      =====      ====      =======      =====
</TABLE>
 
- ---------------
 
(1) In connection with the EDC Acquisition, Samedan's in-house engineers
    prepared estimates of the proved reserves of EDC based on geological and
    engineering evaluations as of December 31, 1995. Prior to closing of the EDC
    Acquisition, Miller and Lents, Ltd., independent petroleum consultants,
    estimated the proved reserves of EDC as of July 1, 1996. A summary of such
    estimates, together with a summary of the estimates of EDC's proved reserves
    prepared by Samedan as of July 31, 1996 (the closing date of the EDC
    Acquisition), is set forth in the Company's Form 8-K (Date of Event: July
    31, 1996), as amended, which is incorporated by reference in this
    Prospectus. After taking into account adjustments for EDC's production and
    exploration and development activities during 1996, there are no material
    differences in the aggregate among such estimate of proved reserves prepared
    by Miller and Lents, Ltd. and the estimates of proved reserves prepared by
    Samedan as of December 31, 1995 and July 31, 1996.
 
     Samedan's in-house engineers annually estimate the Company's proved
reserves, and Samedan does not employ independent engineers to prepare, review
or audit such estimates.
 
     Because of the direct relationship between quantities of proved undeveloped
reserves and development plans, Samedan has assigned to undeveloped locations
only those reserves that will definitely be drilled, and only those reserves
assigned to the undeveloped portions of secondary or tertiary projects that will
definitely be developed have been included in proved reserves and proved
undeveloped reserves. The Company has interests in certain tracts that may have
additional hydrocarbon quantities that were not classified at the time of the
estimate as proved reserves because Samedan did not have definitive plans at
such time to drill or develop these tracts, but which tracts may be reclassified
as proved reserves in the future as a result of the Company's exploration and
development programs. Under the regulations of the Commission, a company may
classify reserves as proved undeveloped reserves, assuming they otherwise meet
the Commission's criteria for proved reserves, without regard to whether such
company has definitive plans to drill or develop such reserves.
 
     There are numerous uncertainties inherent in estimating quantities of
proved oil and gas reserves and in projecting the future rates of production and
timing of development expenditures. Oil and gas reserve engineering is a
subjective process of estimating underground accumulations of oil and gas that
cannot be precisely measured, and estimates of other engineers might differ
materially from the estimates contained or
 
                                        6
<PAGE>   8
 
incorporated by reference in this Prospectus. The accuracy of any reserve
estimate is a function of the quality of available data and of engineering and
geological interpretation and judgment. Results of drilling, testing and
production subsequent to the date of the estimate may justify revision of such
estimate. Accordingly, reserve estimates are often different from the quantities
of oil and gas that are ultimately recovered. In addition, estimates of the
standardized measure of discounted future net cash flows attributable to the
Company's proved reserves are based on certain assumptions regarding future oil
and gas prices, production levels, and operating and development costs that may
not prove to be correct. Any significant variance in these assumptions could
materially affect the estimated quantities of proved reserves and future net
cash flows therefrom contained or incorporated by reference in this Prospectus.
 
     The Company periodically estimates restoration and abandonment costs
relating to its oil and gas properties that will be required to be paid at the
end of the properties' productive lives. The estimated costs, as adjusted from
time to time, are recorded by charges to depreciation, depletion and
amortization expense in the Company's financial statements. The estimated
restoration and abandonment costs are also included in estimated future
production and development costs for purposes of estimating the future net cash
flows attributable to the Company's proved reserves.
 
HEDGING ARRANGEMENTS
 
     The Company, from time to time, uses various hedging arrangements in
connection with anticipated crude oil and natural gas sales to minimize the
impact of product price fluctuations. Such arrangements include fixed price
hedges, costless collars and other contractual arrangements. As of September 30,
1996, the Company was a party to crude oil hedging contracts to hedge
approximately 73 percent of its estimated 1996 fourth quarter crude oil
production and approximately ten percent of its estimated 1997 annual crude oil
production at an average price per bbl of $19.31 and $20.48, respectively. The
Company was also a party as of such date to natural gas hedging contracts to
hedge approximately 48 percent of its estimated 1996 fourth quarter natural gas
production and approximately 28 percent of its estimated 1997 annual natural gas
production at an average price per MMBTU of $1.90 and $1.96, respectively.
 
     Although these hedging arrangements expose the Company to credit risks, the
Company monitors the creditworthiness of its counterparties, which generally are
major institutions, and believes that losses from nonperformance are unlikely to
occur.
 
                                        7
<PAGE>   9
 
                                USE OF PROCEEDS
 
     The net proceeds from the sale of the Common Stock to the Purchaser
pursuant to the arrangements described herein under "Standby Arrangements" will
be used to fund the redemption of any Notes not surrendered for conversion. Any
excess net proceeds, resulting from the Purchaser's remitting certain amounts to
the Company (see "Standby Arrangements"), will be used for general corporate
purposes and, pending such uses, are anticipated to be invested in short-term,
interest-bearing investments.
 
                   PRICE RANGE OF COMMON STOCK AND DIVIDENDS
 
     The Company's Common Stock is traded on the New York Stock Exchange under
the symbol "NBL." The following table sets forth, for the periods indicated, the
high and low sale prices per share of Common Stock on the New York Stock
Exchange and the quarterly dividends per share paid on the Common Stock.
 
<TABLE>
<CAPTION>
                                                                    HIGH     LOW    DIVIDEND
                                                                    -----   -----   --------
    <S>                                                             <C>     <C>     <C>
    1994
      First quarter...............................................  $28 3/4 $23 3/8  $ 0.04
      Second quarter..............................................   32 1/4  22 1/2    0.04
      Third quarter...............................................   30 7/8  25 1/4    0.04
      Fourth quarter..............................................   30 3/8  22 1/2    0.04
    1995
      First quarter...............................................  $27 1/2 $21 1/4  $ 0.04
      Second quarter..............................................   29      25 1/2    0.04
      Third quarter...............................................   29 1/8  23 5/8    0.04
      Fourth quarter..............................................   30 1/2  22 5/8    0.04
    1996
      First quarter...............................................  $33 3/8 $26 7/8  $ 0.04
      Second quarter..............................................   38 3/8  32 1/8    0.04
      Third quarter...............................................   42 1/2  37 3/8    0.04
      Fourth quarter (through October 16).........................   45 1/8  41 5/8
</TABLE>
 
     A recent reported last sale price of the Common Stock appears on the cover
page of this Prospectus.
 
     While the Company currently intends to continue a policy of paying modest
cash dividends, the declaration and amount of future dividends, if any, will be
dependent upon general business conditions, the financial condition and needs of
the Company, the amount of funds legally available for the payment of such
dividends and various other factors.
 
                                        8
<PAGE>   10
 
                                 CAPITALIZATION
 
     The following table sets forth the capitalization of the Company (including
current installments of long-term debt) as of June 30, 1996 (i) on an actual
basis, (ii) pro forma for the EDC Acquisition and the financing thereof and
(iii) as adjusted to give effect to the assumed conversion of $230,000,000
principal amount of Notes into 6,275,579 shares of Common Stock, net of the
Purchaser's standby fee and the estimated expenses payable by the Company in
connection with the offering made hereby.
 
<TABLE>
<CAPTION>
                                                                        JUNE 30, 1996
                                                            -------------------------------------
                                                                                       PRO FORMA
                                                                           PRO            AS
                                                             ACTUAL      FORMA(1)     ADJUSTED(1)
                                                            --------    ----------    -----------
                                                                       (IN THOUSANDS)
<S>                                                         <C>         <C>           <C>
Long-term debt (including current installments):
  7 1/4% Notes due October 15, 2023.......................  $ 99,010    $   99,010    $    99,010
  4 1/4% Convertible Subordinated Notes due November 1,
     2003(2)..............................................   230,000       230,000             --
  Bank credit agreement ($100 million limit)(3)...........    48,000            --             --
  Bank credit agreement ($800 million limit)(3)...........        --       800,000        800,000
                                                            --------    ----------       --------
       Total long-term debt (including current
          installments)...................................   377,010     1,129,010        899,010
                                                            --------    ----------       --------
Shareholders' equity:
  Common stock(4).........................................   173,004       173,004        193,923
  Capital in excess of par value(5).......................   147,368       147,368        353,616
  Retained earnings.......................................   145,378       145,378        145,378
  Less common stock in treasury, at cost..................   (15,418)      (15,418)       (15,418)
                                                            --------    ----------       --------
       Total shareholders' equity.........................   450,332       450,332        677,499
                                                            --------    ----------       --------
          Total capitalization............................  $827,342    $1,579,342    $ 1,576,509
                                                            ========    ==========       ========
</TABLE>
 
- ---------------
 
(1) Gives effect to the EDC Acquisition and the financing thereof as if they
     occurred on June 30, 1996.
 
(2) The Company has called all of the Notes for redemption on November 1, 1996.
 
(3) In connection with the EDC Acquisition, the Company entered into an $800
     million bank credit facility as of July 31, 1996. Borrowings under such
     credit facility were used to fund the purchase price for EDC and, together
     with funds on hand, to repay $48 million of outstanding indebtedness under
     its then existing $100 million bank credit agreement. See "The
     Company -- Business Strategy -- EDC Acquisition."
 
(4) Outstanding shares of Common Stock aggregated 50,376,929 actual and pro
     forma and 56,652,508 pro forma as adjusted. Such amounts exclude 1,859,492
     shares of Common Stock reserved for issuance under the Company's stock
     option plans.
 
(5) Under the agreement described under "Standby Arrangements," the Purchaser
     has agreed, subject to certain conditions, to purchase from the Company a
     number of shares of Common Stock equal to the total number of shares of
     Common Stock that would have been issued upon conversion of any Notes that
     are not duly surrendered for conversion prior to the expiration of
     convertibility on the Redemption Date, at a purchase price equal to the
     aggregate Redemption Price paid by the Company for the Notes not
     surrendered for conversion. Any such purchase will result in the payment by
     the Company of certain additional amounts to the Purchaser. See "Standby
     Arrangements."
 
                                        9
<PAGE>   11
 
                            SELECTED FINANCIAL DATA
 
     The following table sets forth certain consolidated (i) historical
financial data of the Company for each of the three years in the period ended
December 31, 1995 and for the six months ended June 30, 1995 and 1996 and (ii)
pro forma financial data of the Company that give effect to the EDC Acquisition
and the financing thereof which occurred on July 31, 1996. Financial statement
data for the historical interim periods are unaudited but, in the opinion of
management, include all adjustments (which include only normal recurring
accruals) necessary for a fair presentation of the information. Pro forma
financial data also are unaudited. The results of operations for interim periods
are not necessarily indicative of results for the entire year. The table should
be read in conjunction with (i) the Consolidated Financial Statements and
related notes thereto and "Management's Discussion and Analysis of Financial
Condition and Results of Operations" incorporated in this Prospectus by
reference to the Company's Form 10-K for the year ended December 31, 1995, as
amended, and Form 10-Q for the quarter ended June 30, 1996 and (ii) the
Consolidated Financial Statements and related notes thereto of EDC and the Pro
Forma Consolidated Condensed Financial Statements and related notes thereto
incorporated in this Prospectus by reference to the Company's Form 8-K (Date of
Event: July 31, 1996), as amended.
<TABLE>
<CAPTION>
                                                         COMPANY HISTORICAL
                                      ---------------------------------------------------------          PRO FORMA(1)
                                                                               SIX MONTHS         --------------------------
                                                                                  ENDED                           SIX MONTHS
                                          YEAR ENDED DECEMBER 31,               JUNE 30,           YEAR ENDED       ENDED
                                      --------------------------------    ---------------------   DECEMBER 31,     JUNE 30,
                                         1993        1994       1995        1995        1996          1995           1996
                                      ----------   --------   --------    --------   ----------   ------------    ----------
                                                                               (UNAUDITED)               (UNAUDITED)
 
                                                             (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                   <C>          <C>        <C>         <C>        <C>          <C>             <C>
INCOME STATEMENT DATA:
Revenues:
  Gas and oil sales and royalties...  $  278,004   $306,169   $328,134    $154,291   $  227,937     $532,184      $ 349,011
  Gathering, marketing and
    processing......................          --     43,921    112,702      42,086      122,087      202,751        183,861
  Other income......................       8,579      8,299     46,182(2)    2,607        3,971      107,822(3)       7,477
                                      ----------   --------   --------    --------   ----------     --------      ----------
        Total.......................     286,583    358,389    487,018     198,984      353,995      842,757        540,349
                                      ----------   --------   --------    --------   ----------     --------      ----------
Costs and expenses:
  Oil and gas operations............      75,110     74,661     81,735      40,733       49,358       90,165         78,991
  Oil and gas exploration...........      36,473     54,321     33,246      11,395       20,455      110,058         42,164
  Gathering, marketing and
    processing......................          --     42,758    107,867      41,589      110,895      193,472        168,896
  Depreciation, depletion and
    amortization....................     107,215    127,470    200,914(4)   70,820       82,926      335,563(4)     151,446
  Selling, general and
    administrative..................      31,784     36,408     36,514      18,995       18,885       49,908         23,837
  Interest, net of amount
    capitalized.....................      15,342     17,546     18,744       9,315        9,799       63,470         32,430
                                      ----------   --------   --------    --------   ----------     --------      ----------
        Total.......................     265,924    353,164    479,020     192,847      292,318      842,636        497,764
                                      ----------   --------   --------    --------   ----------     --------      ----------
Income before taxes.................      20,659      5,225      7,998       6,137       61,677          121         42,585
Income tax provision................       8,034      2,059      3,912       2,340       22,139           48         13,569
                                      ----------   --------   --------    --------   ----------     --------      ----------
Net income..........................  $   12,625   $  3,166   $  4,086    $  3,797   $   39,538     $     73      $  29,016
                                      ==========   ========   ========    ========   ==========     ========      ==========
Primary earnings per share..........  $      .26   $    .06   $    .08    $    .08   $      .78     $    .00      $     .58
                                      ==========   ========   ========    ========   ==========     ========      ==========
Fully diluted earnings per
  share(5)..........................  $      .26   $    .06   $    .08    $    .08   $      .75     $    .00      $     .56
                                      ==========   ========   ========    ========   ==========     ========      ==========
Cash dividends per share............  $      .16   $    .16   $    .16    $    .08   $      .08     $    .16      $     .08
                                      ==========   ========   ========    ========   ==========     ========      ==========
OTHER FINANCIAL DATA:
Net cash provided by operating
  activities........................  $  139,381   $188,621   $238,920    $120,034   $  155,962
Capital expenditures................     510,113    161,344    259,242     104,111      130,792
BALANCE SHEET DATA (AT PERIOD END):
Property, plant and equipment,
  net...............................  $  794,605   $813,380   $843,945    $837,567   $  885,462                  $1,621,246
Total assets........................   1,067,996    933,516    989,176     959,277    1,055,804                   1,856,154
Long-term debt (including current
  installments).....................     453,760    376,956    376,992     376,974      377,010                   1,129,010
Shareholders' equity................     415,432    412,066    411,911     412,296      450,332                     450,332
</TABLE>
 
- ---------------
 
(1) The pro forma financial data assume the EDC Acquisition and the financing
    thereof occurred at the beginning of the respective periods for income
    statement data and on June 30, 1996 for balance sheet data.
(2) Includes $39 million related to the settlement of a Columbia Gas
    Transmission Corporation bankruptcy claim.
(3) Includes $74 million ($39 million for the Company and $35 million for EDC)
    related to the settlement of Columbia Gas Transmission Corporation
    bankruptcy claims.
(4) Includes a $59.5 million charge related to the write-down of certain assets
    in connection with the Company's adoption in 1995 of Financial Accounting
    Standards No. 121.
(5) Amounts shown were computed using the "if converted method" assuming the
    Notes were converted into Common Stock at the beginning of the period. The
    Notes were antidilutive for all periods ending on or before December 31,
    1995.
 
                                       10
<PAGE>   12
 
                          DESCRIPTION OF CAPITAL STOCK
 
     The Company is authorized to issue 100,000,000 shares of Common Stock, par
value $3.33 1/3 per share, and 4,000,000 shares of Preferred Stock, par value
$1.00 per share ("Preferred Stock"). The following summary description of
capital stock is qualified in its entirety by reference to the Company's
Certificate of Incorporation, as amended, a copy of which is available for
examination at the principal office of the Company and has been filed with the
Commission.
 
COMMON STOCK
 
     Each share of Common Stock is entitled to one vote on all matters submitted
to a vote of stockholders. Dividends may be paid to the holders of Common Stock
when and if declared by the Board of Directors out of funds legally available
for dividends, subject to any preferential and cumulative dividend rights of any
Preferred Stock outstanding at the time. Holders of Common Stock have no
conversion, redemption, cumulative voting or preemptive rights. In the event of
any liquidation, dissolution or winding up of the affairs of the Company,
holders of Common Stock would be entitled to share ratably in its assets
remaining after provision for payment of creditors and after the liquidation
preference of any Preferred Stock outstanding at the time.
 
     Under the Company's Certificate of Incorporation, the affirmative vote of
the holders of 75 percent of the issued and outstanding stock having voting
power is required to authorize a merger, consolidation or the sale, lease or
exchange of substantially all of the assets of the Company.
 
     In addition, the Company's Certificate of Incorporation contains a "fair
price" provision designed to prevent a purchaser from utilizing two-tier pricing
and similar inequitable tactics in the event of an attempt to take over the
Company. The provision requires, as a condition for mergers and certain other
business transactions of the Company with any holder of 20 percent or more of
the voting power of the outstanding shares of stock of the Company entitled to
vote in the election of directors, that such entity satisfy certain minimum
price and procedural requirements.
 
     All outstanding shares of Common Stock are, and the shares of Common Stock
to be issued upon the conversion of the Notes or upon issuance by the Company
pursuant to the agreement described under "Standby Arrangements" will be, fully
paid and nonassessable.
 
     The transfer agent and register for the Common Stock is Liberty Bank and
Trust Company of Oklahoma City, N.A., 100 North Broadway, Oklahoma City,
Oklahoma 73102.
 
PREFERRED STOCK
 
     Although the Company has no Preferred Stock outstanding and has no present
plans to issue any of such stock, the Company's Board of Directors is authorized
to issue shares of Preferred Stock from time to time without further stockholder
action. The Board of Directors has power to fix various terms with respect to
each series of Preferred Stock, including dividend rights and preferences,
redemption prices, sinking fund terms, conversion rights and prices, voting
rights, if any, and rights upon any liquidation, dissolution or winding up of
the affairs of the Company. The terms of any Preferred Stock that may be issued
could discourage or make more difficult any potential takeover proposals.
 
                                       11
<PAGE>   13
 
                              STANDBY ARRANGEMENTS
 
     Under a Standby Agreement (the "Standby Agreement") between the Company and
UBS Securities LLC (the "Purchaser"), the Purchaser has agreed, subject to
certain conditions, to purchase from the Company a number of shares of Common
Stock equal to the total number of shares of Common Stock that would have been
issued upon conversion of (i) those Notes that are duly surrendered for
redemption prior to 5:00 P.M., New York City time, on the Redemption Date and
(ii) those Notes that are not duly surrendered for conversion or redemption
("Nonresponse Redemption Shares") prior to 5:00 P.M., New York City time, on the
Redemption Date (the number of shares so purchased being hereinafter
collectively referred to as the "Purchased Shares"). The purchase price for the
Purchased Shares will be $37.74 per share (the "Purchase Price"). The Company
will apply the net proceeds received from the Purchaser toward payment of the
Redemption Price of the Notes.
 
     The Purchaser may also purchase Notes in the open market or otherwise prior
to the expiration of convertibility on the Redemption Date.
 
     The Company has been advised by the Purchaser that it proposes to offer any
shares of Common Stock purchased from the Company or acquired upon conversion of
Notes for resale as set forth on the cover page of this Prospectus. The
Purchaser may also make sales of such shares to dealers at prices which
represent concessions from the prices at which the shares are then being offered
to the public. The amounts of such concessions are to be determined from time to
time by the Purchaser.
 
     The Company has agreed to pay compensation to the Purchaser for the
commitments undertaken by it under the Standby Agreement in the amount of
$2,368,425 as a standby fee and an amount per Purchased Share (excluding any
Nonresponse Redemption Shares) as follows: as to the number of shares purchased
up to 627,557 shares, 2.75 percent of the Purchase Price; as to any additional
shares purchased up to 1,882,673 shares, 3.75 percent of the Purchase Price; as
to any additional shares purchased up to 3,137,789 shares, 4.75 percent of the
Purchase Price; and as to any additional shares purchased, 6.50 percent of the
Purchase Price. Thus, only the $2,368,425 standby fee would be received by the
Purchaser if all the currently outstanding Notes are converted by the holders
prior to the expiration of convertibility on the Redemption Date, and the
maximum compensation would be $14,743,334 if all of the currently outstanding
Notes are redeemed. Any profits realized by the Purchaser upon resale of the
Nonresponse Redemption Shares will be shared equally by the Company and the
Purchaser. The Purchaser's share of such profits may also be deemed to be
underwriting compensation within the meaning of the Securities Act. In addition,
the Purchaser has agreed to advance to the Company monies, if any, required for
deposit with the Trustee pursuant to the terms of the Indenture with the Company
reimbursing the Purchaser for the cost of any such deposit. The Company has
agreed to reimburse the Purchaser for its reasonable out-of-pocket expenses,
including the fees and disbursements of its counsel.
 
     During the period beginning on the date of this Prospectus and continuing
through the Redemption Date, and, if the Purchaser purchases any Purchased
Shares, further continuing through the date ending 90 days after the Redemption
Date, the Company has agreed not to offer, sell, contract to sell or otherwise
dispose of any shares of Common Stock or any securities convertible into or
exchangeable for shares of Common Stock, with certain exceptions, without the
prior written consent of the Purchaser.
 
     The Company has agreed to indemnify the Purchaser against certain
liabilities, including liabilities under the Securities Act.
 
     In the ordinary course of their regular business, the Purchaser and certain
affiliates of the Purchaser may provide investment banking and commercial
banking services to the Company.
 
                                       12
<PAGE>   14
 
                            VALIDITY OF COMMON STOCK
 
     The validity of the Common Stock offered hereby will be passed upon for the
Company by Thompson & Knight, P.C., Dallas, Texas, and for the Purchaser by
Sullivan & Cromwell, New York, New York. Harold F. Kleinman, a shareholder of
Thompson & Knight, P.C., is a director of the Company and is the beneficial
owner of 200 shares of Common Stock.
 
                                    EXPERTS
 
     The consolidated financial statements of Noble Affiliates, Inc.
incorporated by reference in this Prospectus, to the extent and for the periods
indicated in their report, have been audited by Arthur Andersen LLP, independent
public accountants, and are incorporated by reference herein in reliance upon
the authority of said firm as experts in accounting and auditing in giving said
reports. Reference is made to said report, which includes an explanatory
paragraph with respect to the adoption of Statement of Financial Accounting
Standards No. 121, "Accounting for the Impairment of Long-Lived Assets and for
Long-Lived Assets to Be Disposed Of" as discussed in Note 9 to the consolidated
financial statements.
 
     The consolidated financial statements of EDC, incorporated by reference in
this Prospectus, to the extent and for the periods indicated in their report,
have been incorporated herein in reliance on the report of Deloitte & Touche
LLP, independent auditors, given upon the authority of such firm as experts in
accounting and auditing.
 
     Estimates of EDC's proved reserves as of July 1, 1996 prepared by Miller
and Lents, Ltd., independent petroleum consultants, are set forth in the
Company's Form 8-K (Date of Event: July 31, 1996), as amended, which is
incorporated by reference in this Prospectus. Such estimates are incorporated by
reference herein in reliance upon the authority of said firm as experts in
estimating proved reserves.
 
                                       13
<PAGE>   15
 
================================================================================
 
     NO DEALER, SALESPERSON OR OTHER PERSON HAS BEEN AUTHORIZED TO GIVE ANY
INFORMATION OR TO MAKE ANY REPRESENTATIONS NOT CONTAINED OR INCORPORATED BY
REFERENCE IN THIS PROSPECTUS AND, IF GIVEN OR MADE, SUCH INFORMATION OR
REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED BY THE COMPANY
OR THE PURCHASER. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR THE
SOLICITATION OF AN OFFER TO BUY ANY OF THE SECURITIES OFFERED HEREBY IN ANY
JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER IN SUCH
JURISDICTION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE
HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE AN IMPLICATION THAT THE
INFORMATION HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE DATE HEREOF OR
THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE SUCH DATE.
 
                             ---------------------
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                         PAGE
                                         ----
<S>                                      <C>
Disclosure Regarding Forward-Looking
  Statements..........................     2
Oil and Gas Terminology...............     2
Available Information.................     3
Incorporation of Certain Documents by
  Reference...........................     3
The Company...........................     4
Use of Proceeds.......................     8
Price Range of Common Stock and
  Dividends...........................     8
Capitalization........................     9
Selected Financial Data...............    10
Description of Capital Stock..........    11
Standby Arrangements..................    12
Validity of Common Stock..............    13
Experts...............................    13
</TABLE>
 
================================================================================
 
================================================================================

                                6,275,579 SHARES

 
                             NOBLE AFFILIATES, INC.

                                  COMMON STOCK
                                   PROSPECTUS
 
                                 UBS SECURITIES

                                OCTOBER 17, 1996

================================================================================
<PAGE>   16
 
                                    PART II
 
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.
 
     Except for the SEC registration fee, all expenses are estimated. All such
expenses will be paid by the Registrant.
 
<TABLE>
    <S>                                                                 <C>
    SEC registration fee..............................................  $ 83,675
    Accounting fees and expenses......................................   160,000
    Legal fees and expenses...........................................   190,000
    Printing expenses.................................................    20,000
    Blue sky fees and expenses (including legal fees).................     5,500
    Miscellaneous.....................................................     5,825
                                                                        --------
              Total...................................................  $465,000
                                                                        ========
</TABLE>
 
ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
     The Registrant is a Delaware corporation. Under Section 145 of the General
Corporation Law of the State of Delaware, the Registrant has the power to
indemnify its directors and officers, subject to certain limitations.
 
     Reference is made to Article VI of the Bylaws of the Registrant, which
Article is filed as part of Exhibit 3.2 hereto and provides for indemnification
of directors and officers of the Registrant under certain circumstances.
 
     Pursuant to the General Corporation Law of the State of Delaware, the
Certificate of Incorporation of the Registrant, filed as Exhibit 4.1 hereto,
limits the personal liability of the directors of the Registrant to the
Registrant or its stockholders for monetary damages for breach of fiduciary duty
under certain circumstances.
 
     The Registrant entered into an Indemnity Agreement with each of the
directors and bylaw officers of the Registrant as of March 1, 1996 which
provides certain protections to such persons against legal claims and related
expenses. The Indemnity Agreements are filed as Exhibit 10.18 to the
Registrant's Form 10-K for the year ended December 31, 1995.
 
     The Registrant also maintains insurance to protect itself and its
directors, officers, employees and agents against expenses, liabilities and
losses incurred by such persons in connection with their service in the
foregoing capacities.
 
     The foregoing summaries are necessarily subject to the complete text of the
statute, bylaw, agreement, certificate of incorporation and insurance policy
referred to above and are qualified in their entirety by reference thereto.
 
ITEM 16. EXHIBITS.
 
     The following exhibits are filed as part of this Registration Statement:
 
<TABLE>
<CAPTION>
       NUMBER                                        EXHIBIT
- -------------------- ------------------------------------------------------------------------
<C>                  <S>
         1.1         -- Form of Standby Agreement between the Registrant and UBS Securities
                        LLC.
         2.1         -- Stock Purchase Agreement dated as of July 1, 1996, between Samedan
                        Oil Corporation and Enterprise Diversified Holdings Incorporated
                        (filed as Exhibit 2.1 to the Registrant's Current Report on Form 8-K
                        (Date of Event: July 31, 1996) dated August 13, 1996 and incorporated
                        herein by reference).
         3.1         -- Certificate of Incorporation, as amended, of the Registrant as
                        currently in effect (filed as Exhibit 3.2 to the Registrant's Annual
                        Report on Form 10-K for the year ended December 31, 1987 and
                        incorporated herein by reference).
</TABLE>
 
                                      II-1
<PAGE>   17
 
<TABLE>
<CAPTION>
       NUMBER                                        EXHIBIT
- -------------------- ------------------------------------------------------------------------
<C>                  <S>
         3.2         -- Composite copy of the Bylaws of the Registrant as currently in effect
                        (filed as Exhibit 3.2 to the Registrant's Annual Report on Form 10-K
                        for the year ended December 31, 1992 and incorporated herein by
                        reference).
         4.1         -- Credit Agreement dated as of July 31, 1996 among the Registrant, as
                        borrower, certain commercial lending institutions which are or may
                        become a party thereto, as lenders (filed as Exhibit 10.1 to the
                        Registrant's current report on Form 8-K (Date of Event: July 31,
                        1996), filed on August 13, 1996 and incorporated herein by
                        reference).
         4.2         -- First Amendment to Credit Agreement dated as of October 15, 1996
                        among the Registrant, as borrower, certain commercial lending
                        institutions which are or may become parties thereto, as lenders, and
                        Union Bank of Switzerland, Houston Agency, as agent for the lenders.
         5.1         -- Opinion of Thompson & Knight, P.C.
        23.1         -- Consent of Arthur Andersen LLP.
        23.2         -- Consent of Deloitte & Touche LLP.
        23.3         -- Consent of Thompson & Knight, P.C. (included in their opinion filed
                        as Exhibit 5.1).
        23.4         -- Consent of Miller & Lents, Ltd.
        24.1         -- Powers of Attorney Authorizing Signatures (contained on Signature
                        Pages included in Part II of the Registration Statement).
</TABLE>
 
ITEM 17. UNDERTAKINGS.
 
  (a) Rule 415 offering.
 
     The undersigned Registrant hereby undertakes:
 
          (1) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this Registrant Statement:
 
             (i) To include any prospectus required by Section 10(a)(3) of the
        Securities Act of 1933;
 
             (ii) To reflect in the prospectus any facts or events arising after
        the effective date of the Registration Statement (or the most recent
        post-effective amendment thereof) which, individually or in the
        aggregate, represent a fundamental change in the information set forth
        in the Registration Statement; and
 
             (iii) To include any material information with respect to the plan
        of distribution not previously disclosed in the Registration Statement
        or any material change to such information in the Registration
        Statement;
 
     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) above do not
     apply if the information required to be included in a post-effective
     amendment by those paragraphs is contained in periodic reports filed with
     or furnished to the Commission by the Registrant pursuant to section 13 or
     section 15(d) of the Securities Exchange Act of 1934 that are incorporated
     by reference in the Registration Statement.
 
          (2) That, for the purpose of determining any liability under the
     Securities Act of 1933, each such post-effective amendment shall be deemed
     to be a new registration statement relating to the securities offered
     therein, and the offering of such securities at that time shall be deemed
     to be the initial bona fide offering thereof.
 
          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.
 
                                      II-2
<PAGE>   18
 
  (b) Filings incorporating subsequent Exchange Act documents by reference.
 
     The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's Annual Report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 that is incorporated by reference in the
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
  (h) Acceleration of effectiveness.
 
     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Registrant of expenses incurred
or paid by a director, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.
 
                                      II-3
<PAGE>   19
 
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Houston, State of Texas, on the 16th day of October,
1996.
 
                                            NOBLE AFFILIATES, INC.
 
                                            By:     /s/  ROBERT KELLEY
                                            ------------------------------------
                                                       Robert Kelley
                                                   Chairman of the Board,
                                               President and Chief Executive
                                                          Officer
 
     Each person whose signature appears below constitutes and appoints Robert
Kelley and William D. Dickson, and each of them (with full power to each of them
to act alone), his true and lawful attorney-in-fact and agent, with full power
of substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities to sign on his behalf individually and in each capacity
stated below any amendment (including post-effective amendments), to this
Registration Statement and any Registration Statement (including any amendment
thereto) for this offering that is to be effective upon filing pursuant to Rule
462(b) under the Securities Act of 1933, as amended, and to file the same, with
all exhibits thereto and other documents in connection therewith with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and
agents and either of them, or their substitutes, may lawfully do or cause to be
done by virtue hereof.
 
     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
            SIGNATURE AND TITLES                                     DATE
- ---------------------------------------------    ---------------------------------------------
<S>                                              <C>
             /s/  ROBERT KELLEY                                October 16, 1996
- ---------------------------------------------
                Robert Kelley
   Chairman of the Board, President, Chief
  Executive Officer and Director (Principal
             Executive Officer)

           /s/  WILLIAM D. DICKSON                             October 16, 1996
- ---------------------------------------------
             William D. Dickson
   Vice President -- Finance and Treasurer
(Principal Financial and Accounting Officer)

             /s/  ALAN A. BAKER                                October 16, 1996
- ---------------------------------------------
                Alan A. Baker
                  Director

           /s/  MICHAEL A. CAWLEY                              October 16, 1996
- ---------------------------------------------
              Michael A. Cawley
                  Director

             /s/  EDWARD F. COX                                October 16, 1996
- ---------------------------------------------
                Edward F. Cox
                  Director
</TABLE>
 
                                      II-4
<PAGE>   20
 
<TABLE>
<CAPTION>
            SIGNATURE AND TITLES                                     DATE
- ---------------------------------------------    ---------------------------------------------
<S>                                              <C>
              /s/  JAMES C. DAY                                October 16, 1996
- ---------------------------------------------
                James C. Day
                  Director

            /s/  HAROLD KLEINMAN                               October 16, 1996
- ---------------------------------------------
               Harold Kleinman
                  Director

            /s/  GEORGE J. McLEOD                              October 16, 1996
- ---------------------------------------------
              George J. McLeod
                  Director
</TABLE>
 
                                      II-5
<PAGE>   21
 
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
       NUMBER                                        EXHIBIT
- -------------------- ------------------------------------------------------------------------
<C>                  <S>
         1.1         -- Form of Standby Agreement between the Registrant and UBS Securities
                        LLC.
         2.1         -- Stock Purchase Agreement dated as of July 1, 1996, between Samedan
                        Oil Corporation and Enterprise Diversified Holdings Incorporated
                        (filed as Exhibit 2.1 to the Registrant's Current Report on Form 8-K
                        (Date of Event: July 31, 1996) dated August 13, 1996 and incorporated
                        herein by reference).
         3.1         -- Certificate of Incorporation, as amended, of the Registrant as
                        currently in effect (filed as Exhibit 3.2 to the Registrant's Annual
                        Report on Form 10-K for the year ended December 31, 1987 and
                        incorporated herein by reference).
         3.2         -- Composite copy of the Bylaws of the Registrant as currently in effect
                        (filed as Exhibit 3.2 to the Registrant's Annual Report on Form 10-K
                        for the year ended December 31, 1992 and incorporated herein by
                        reference).
         4.1         -- Credit Agreement dated as of July 31, 1996 among the Registrant, as
                        borrower, certain commercial lending institutions which are or may
                        become a party thereto, as lenders (filed as Exhibit 10.1 to the
                        Registrant's current report on Form 8-K (Date of Event: July 31,
                        1996), filed on August 13, 1996 and incorporated herein by
                        reference).
         4.2         -- First Amendment to Credit Agreement dated as of October 15, 1996
                        among the Registrant, as borrower, certain commercial lending
                        institutions which are or may become parties thereto, as lenders, and
                        Union Bank of Switzerland, Houston Agency, as agent for the lenders.
         5.1         -- Opinion of Thompson & Knight, P.C.
        23.1         -- Consent of Arthur Andersen LLP.
        23.2         -- Consent of Deloitte & Touche LLP.
        23.3         -- Consent of Thompson & Knight, P.C. (included in their opinion filed
                        as Exhibit 5.1).
        23.4         -- Consent of Miller & Lents, Ltd.
        24.1         -- Powers of Attorney Authorizing Signatures (contained on Signature
                        Pages included in Part II of the Registration Statement).
</TABLE>

<PAGE>   1
                                                                     EXHIBIT 1.1

                                                       Draft of October 16, 1996


                             NOBLE AFFILIATES, INC.

           4 1/4% Convertible Subordinated Notes due November 1, 2003

                               STANDBY AGREEMENT

                                                                October 17, 1996

UBS Securities LLC
299 Park Avenue
New York, New York 10171

Ladies and Gentlemen:

              Noble Affiliates, Inc., a Delaware corporation (the "Company"),
proposes to call for redemption on November 1, 1996 (the "Redemption Date") all
of its outstanding 4 1/4% Convertible Subordinated Notes due November 1, 2003
(the "Notes") at a redemption price of $1,029.75 for each $1,000 principal
amount thereof (the "Redemption Price").  The Notes are convertible into shares
of the Company's Common Stock, par value $3.33 1/3 per share (the "Common
Stock").  The right to convert the Notes into Common Stock will terminate at
5:00 p.m., New York City time, on the Redemption Date.  The Company desires to
make arrangements with you (the "Purchaser") pursuant to which the Purchaser
will purchase authorized but unissued shares of Common Stock which would have
been delivered upon conversion of those Notes which are either (i) duly
surrendered for redemption or (ii) not duly surrendered for conversion or
redemption (the "Nonresponse Redemption Shares") prior to 5:00 p.m., New York
City time, on the Redemption Date (collectively, the "Shares"), at a purchase
price equal to $37.74 per share.  The shares of Common Stock purchased by the
Purchaser hereunder, including the Failed Shares (as hereinafter defined), are
referred to herein as the "Purchased Shares".  The Company confirms its
agreement with you as follows.

              SECTION 1.  Representations and Warranties.  The Company
represents and warrants to, and agrees with, you that:

              (a)    The Company has prepared and filed, or will file promptly
       after the execution hereof, with the Securities and Exchange Commission
       (the "Commission") a registration statement on Form S-3 for the
       registration under the Securities Act of 1933, as amended (the "Act"),
       of the Shares.  Such registration statement is in the form heretofore
       (including all documents incorporated by reference in the prospectus
       contained therein) delivered to you or your counsel, and no other
       document with respect to such registration statement or documents
       incorporated by reference has heretofore been filed or transmitted for
       filing with the Commission.  The registration statement, including all
       exhibits thereto and the documents incorporated by reference in the
       prospectus contained in the registration statement at the time the
       registration statement becomes effective, each as amended at the time
       the registration statement becomes effective, and the prospectus
       constituting a part of the registration statement
<PAGE>   2
       on file with the Commission at the time the registration statement
       becomes effective, including the documents incorporated by reference
       therein pursuant to Item 12 of Form S-3 under the Act, are hereinafter
       called the "Registration Statement" and the "Prospectus", respectively,
       except that if any prospectus shall be filed with the Commission and
       provided to the Purchaser by the Company for use in connection with the
       offering of the Common Stock by the Purchaser which differs from the
       Prospectus on file with the Commission at the time the Registration
       Statement becomes effective (whether or not such Prospectus is required
       to be filed by the Company pursuant to Rule 424(b) of the rules and
       regulations of the Commission under the Act), the term "Prospectus"
       shall refer to such prospectus from and after the time it is first
       provided to the Purchaser for such use, and if the Company files any
       documents pursuant to the Securities Exchange Act of 1934, as amended
       (the "Exchange Act"), after the time the Registration Statement becomes
       effective and prior to the termination of the offering of the Common
       Stock by the Purchaser, which documents are deemed to be incorporated by
       reference into the Prospectus, the terms "Registration Statement" and
       "Prospectus" shall refer to said Registration Statement and Prospectus
       as supplemented by the documents so filed from and after the time said
       documents are filed with the Commission.  Any reference herein to the
       terms "amend", "amendment" or "supplement" with respect to the
       Registration Statement or Prospectus shall be deemed to refer to and
       include the filing after the execution hereof of any document with the
       Commission deemed to be incorporated by reference therein.

              (b)    The Registration Statement and any amendment thereto, in
       each case at the time it becomes effective under the Act, will conform
       in all material respects with the requirements of the Act and the rules
       and regulations of the Commission thereunder and will not, as of such
       effective date, contain an untrue statement of a material fact or omit
       to state a material fact required to be stated therein or necessary to
       make the statements therein not misleading, and the Prospectus and any
       amendment or supplement thereto, at the time the Registration Statement
       becomes effective (unless the term "Prospectus" refers to a prospectus
       which has been provided to the Purchaser by the Company for use in
       connection with the offering of Common Stock by the Purchaser which
       differs from the Prospectus on file with the Commission at the time the
       Registration Statement becomes effective, in which case at the time it
       is first provided to the Purchaser for such use) and at all times
       through termination of the offering of the Common Stock by the
       Purchaser, will conform in all material respects with the requirements
       of the Act and the rules and regulations of the Commission thereunder
       and will not, as of the applicable filing date as to the Prospectus and
       any amendment or supplement thereto and as of the time any prospectus
       which differs from the Prospectus on file with the Commission at the
       time the Registration Statement becomes effective is first provided to
       the Purchaser for use, contain an untrue statement of a material fact or
       omit to state a material fact required to be stated therein or necessary
       to make the statements therein not misleading; provided, however, that
       this representation and warranty shall not apply to any statements or
       omissions made in reliance upon and in conformity with information
       furnished in writing to the Company by you expressly for use in the
       Prospectus.  There are no contracts or documents of the Company or any
       of its consolidated subsidiaries which





                                      -2-
<PAGE>   3
       would be required to be filed as exhibits to the Registration Statement
       by the Act or by the rules and regulations of the Commission thereunder
       which have not been filed as exhibits to the Registration Statement.

              (c)    The documents incorporated by reference in the Prospectus,
       when they became effective or were filed with the Commission, as the
       case may be (or, if any amendment with respect to any such document was
       filed, when such amendment was filed), conformed in all material
       respects to the requirements of the Act or the Exchange Act, as
       applicable, and the rules and regulations of the Commission thereunder,
       and none of such documents contained an untrue statement of a material
       fact or omitted to state a material fact required to be stated therein
       or necessary to make the statements therein not misleading, and, when
       considered with the other information in the Prospectus, at the time the
       Registration Statement becomes effective, will not contain an untrue
       statement of a material fact or omit to state a material fact required
       to be stated therein or necessary to make the statements therein not
       misleading; and any further documents filed with the Commission and
       incorporated by reference in the Prospectus or any further amendment or
       supplement thereto, when such documents become effective or are filed
       with the Commission, as the case may be, will conform in all material
       respects to the requirements of the Act or the Exchange Act, as
       applicable, and the rules and regulations of the Commission thereunder
       and will not contain an untrue statement of a material fact or omit to
       state a material fact required to be stated therein or necessary to make
       the statements therein not misleading; provided, however, that this
       representation and warranty shall not apply to any statements or
       omissions made in reliance upon and in conformity with information
       furnished in writing to the Company by you expressly for use in the
       Prospectus.

              (d)    The financial statements of the Company and its
       subsidiaries, including the notes thereto, and the supporting schedules
       included or incorporated by reference in the Registration Statement and
       Prospectus fairly present the financial condition of the Company and its
       subsidiaries as of the dates indicated and the results of operations and
       changes in financial position for the periods therein specified, and
       have been prepared, in conformity with generally accepted accounting
       principles consistently applied throughout the periods involved (except
       as otherwise stated therein).  The pro forma financial information
       included or incorporated by reference in the Registration Statement and
       Prospectus has been prepared in accordance with the rules and
       regulations of the Commission with respect to pro forma financial
       statements, fairly presents the information shown therein and has been
       properly compiled on the pro forma basis described therein; the
       assumptions used in the preparation of such pro forma financial
       information are reasonable and the adjustments used therein are
       appropriate to give effect to the transactions and events referred to
       therein.

              (e)    Neither the Company nor any of its subsidiaries has
       sustained since the date of the latest audited financial statements
       included or incorporated by reference in the Prospectus and prior to the
       Time of Mailing (as hereinafter defined), any loss or interference with
       its business from fire, explosion, flood or other calamity, or from





                                      -3-
<PAGE>   4
       any labor dispute or court or governmental action, order or decree, that
       is material to the Company and its subsidiaries taken as a whole (taking
       into account any insurance proceeds that may have been received),
       otherwise than as set forth or contemplated in the Prospectus (or
       indicated in the financial statements included or incorporated by
       reference therein); and, since the respective dates as of which
       information is given in the Registration Statement and the Prospectus,
       there has been no dividend or distribution of any kind declared, paid or
       made by the Company on any of its Common Stock other than regular
       quarterly dividends.

              (f)    The Company and each of its subsidiaries has been duly
       incorporated and is an existing corporation in good standing under the
       laws of its jurisdiction of incorporation, has full power and authority
       (corporate and other) to conduct its business as described in the
       Registration Statement and Prospectus and is duly qualified to do
       business in each jurisdiction in which its ownership of real property or
       interests therein or the conduct of its business requires such
       qualification except where the failure to be so qualified can be
       remedied without material cost to the Company or, considering all such
       cases in the aggregate, does not involve a material risk to the
       business, properties, financial position or results of operations of the
       Company and its subsidiaries taken as a whole; and all of the
       outstanding shares of capital stock of each such subsidiary have been
       duly authorized and validly issued, are fully paid and non-assessable
       and (except for any directors' qualifying shares or as otherwise stated
       in the Registration Statement) are owned beneficially by the Company
       subject to no security interest or other encumbrance or claim affecting
       transferability or voting.

              (g)    The Company has an authorized capitalization as set forth
       in the Prospectus, and all of the issued shares of capital stock of the
       Company have been duly and validly authorized and issued and are fully
       paid and non-assessable and conform to the description thereof contained
       in the Prospectus; all of the shares of Common Stock to be issued by the
       Company pursuant to this Agreement have been duly authorized and, when
       issued and delivered as contemplated hereby, will be validly issued,
       fully paid and non-assessable and will conform to the description of the
       Common Stock contained in the Prospectus; and the shareholders of the
       Company have no preemptive rights with respect to the Common Stock.

              (h)    Except as contemplated in the Prospectus, subsequent to
       the respective dates as of which information is given in the
       Registration Statement and the Prospectus, neither the Company nor any
       of its subsidiaries has incurred any liabilities or obligations, direct
       or contingent, or entered into any transactions, not in the ordinary
       course of business, that are material to the Company and its
       subsidiaries taken as a whole, and there has not been any material
       change, or any development which could reasonably be expected to involve
       a prospective material change, on a consolidated basis, in the capital
       stock, short-term debt or long-term debt of the Company and its
       subsidiaries, or any material adverse change, or any development which
       could reasonably be expected to involve a prospective material adverse
       change, in the condition (financial or other), business, properties, net
       worth or results of operations of the Company and its subsidiaries taken
       as a whole.





                                      -4-
<PAGE>   5
              (i)    Except as set forth in the Prospectus, there is not
       pending or, to the knowledge of the Company, threatened any action,
       suit, claim, investigation or proceeding to which the Company or any of
       its subsidiaries is a party, before or by any court or governmental
       agency or body, that could reasonably be expected to (i) result in any
       material adverse change in the condition (financial or other), business,
       net worth or results of operations of the Company and its subsidiaries
       taken as a whole, or (ii) materially and adversely affect the
       consolidated properties or assets thereof.

              (j)    There are no contracts or documents of the Company or any
       of its subsidiaries that are required to be filed as exhibits to the
       Registration Statement or to any of the documents incorporated by
       reference therein by the Act or the Exchange Act or by the rules and
       regulations of the Commission thereunder that have not been so filed.

              (k)    The performance of this Agreement and the consummation of
       the transactions herein contemplated, including, without limitation, the
       call of the Notes for redemption, the redemption of the Notes, and the
       issue and sale of the shares of Common Stock by the Company as
       contemplated by this Agreement, will not result in a breach or violation
       of any of the terms and provisions of, or constitute a default under,
       any statute, any agreement or instrument to which the Company is a party
       or by which it is bound or to which any of the property of the Company
       is subject, the Company's charter or by-laws, or any order, rule or
       regulation of any court or governmental agency or body having
       jurisdiction over the Company or any of its properties; no consent,
       approval, authorization or order of, or filing with, any court or
       governmental agency or body is required for the call of the Notes for
       redemption, the redemption of the Notes, the issue and sale of shares of
       Common Stock by the Company as contemplated by this Agreement or the
       consummation by the Company of the transactions contemplated by this
       Agreement, except such as may be required under the Act or state
       securities laws; the Company has full power and authority to authorize,
       issue and sell the shares of Common Stock as contemplated by this
       Agreement; and all taxes, if any, required to be paid by the Company
       with respect to the redemption of the Notes and the issuance of shares
       of Common Stock upon conversion of the Notes or otherwise pursuant to
       this Agreement, have been or will be paid by the Company.

              (l)    Each of the Company and its subsidiaries owns title
       (consistent with customary practice in the oil and gas industry for the
       type and location of the relevant properties and assets) to its material
       oil and gas properties, free and clear of any encumbrances, except for
       liens for taxes or charges of mechanics or materialmen not yet due or
       which are being challenged in good faith, encumbrances under gas sales
       contracts, operating agreements, unitization and pooling agreements and
       other similar agreements as are customarily found in connection with
       comparable operations and title defects that are, singly and in the
       aggregate, not material in amount and do not interfere in any material
       respect with its use or enjoyment of such material oil and gas
       properties.





                                      -5-
<PAGE>   6
              (m)    The Company and each of its subsidiaries carry, or are
       covered by, insurance in such amounts and covering such risks as is
       customary for companies engaged in similar businesses in similar
       industries.

              (n)    Except as described in the Prospectus, there has been no
       storage, disposal, generation, manufacture, spill, discharge,
       refinement, transportation, handling or treatment of toxic wastes,
       hazardous wastes or hazardous substances by the Company or any of its
       subsidiaries (or to the knowledge of the Company, any of its
       predecessors in interest) at, upon or from any of the property now or
       previously owned or leased or under contract for purchase by the Company
       or any of its subsidiaries in violation of any applicable law,
       ordinance, rule, regulation, order, judgment, decree or permit or which
       would require remedial action under any applicable law, ordinance, rule,
       regulation, order, judgment, decree or permit, except for any violation
       or remedial action which would not reasonably be expected to result in,
       singularly or in the aggregate with all such violations and remedial
       actions, any material adverse effect on the consolidated financial
       position, shareholders' equity, results of operations or business of the
       Company and its subsidiaries that has not heretofore been reflected in
       the Company's consolidated financial statements; and the terms
       "hazardous wastes," "toxic wastes" and "hazardous substances" shall have
       the meanings specified in any applicable local, state, federal and
       foreign laws or regulations with respect to environmental protection.

              (o)    At the close of business on October 16, 1996, $230,000,000
       aggregate principal amount of the Notes remained outstanding; the Notes
       are convertible in accordance with the terms of the Indenture between
       the Company and United States Trust Company of New York (the "Trustee")
       dated as of October 14, 1993 (the "Indenture"), until 5:00 p.m., New
       York City time, on the Redemption Date, into Common Stock at a
       conversion price of $36.65 of principal amount of Notes per share of
       Common Stock; and from and after the time the Registration Statement
       becomes effective and until 5:00 p.m., New York City time, on the
       Redemption Date, the Company will take no action which would result in
       any change in the conversion price.

              (p)    No holder of outstanding shares of Common Stock has any
       rights to the registration of shares of Common Stock or other securities
       of the Company which would or could require such securities to be
       included in the Registration Statement.

              (q)    The Company has neither paid nor given, nor will pay or
       give, directly or indirectly, any commission or other remuneration for
       soliciting the conversion of any Notes into Common Stock.

              (r)    The Company has instructed the Trustee to cooperate with
       you in order to facilitate the conversion of Notes acquired by you until
       5:00 p.m., New York City time, on the Redemption Date.

              (s)    The Shares have been listed, subject to notice of
       issuance, on the New York Stock Exchange.





                                      -6-
<PAGE>   7
              Any certificate signed by any officer of the Company and
delivered to you or to your counsel shall be deemed a representation and
warranty by the Company to you as to the matters covered thereby.

              SECTION 2.  Purchase, Sale and Delivery of Shares.  On the basis
of the representations, warranties and agreements herein contained, but subject
to the terms and conditions herein set forth, the Company agrees to issue and
sell to you, and you agree to purchase from the Company, all of the Purchased
Shares at a purchase price of $37.74 per share (the "Purchase Price").

              Promptly after the close of business on the Redemption Date, the
Company shall notify the Purchaser in writing after conferring with the Trustee
of the principal amount of Notes that have been converted.

              The closing (the "Closing") of the purchase and sale of the
Shares shall occur at 10:00 A.M. (New York City time) on November 6, 1996, or
at such other time not later than seven full business days thereafter as the
Purchaser and the Company determine (the "Closing Date"), at the offices of
Thompson & Knight, P.C., 1700 Pacific Avenue, Suite 3300, Dallas, Texas 75201.
Payment for the Shares shall be by wire transfer in immediately available
funds.  The Company will deliver to you certificates evidencing the Purchased
Shares (in definitive form and registered in such names and in such
denominations as you shall request by written notice to the Company).  A
"business day" shall be a day on which the Commission's office in Washington,
D.C., and banks and securities exchanges in New York, New York, are open for
business.  Delivery of the certificates evidencing the Purchased Shares is to
be made at your office at 299 Park Avenue, New York, New York 10171, or as you
may otherwise designate in writing.

              For purposes of expediting the checking and packaging of any
certificates to be delivered at the Closing, the Company shall make
certificates available for inspection at the office of the Purchaser, 299 Park
Avenue, New York, New York 10171, at least 24 hours prior to the Closing.

              As compensation to you for your commitment hereunder the Company
will pay to you, by wire transfer in immediately available funds, (a) on the
date hereof, $2,368,425.00 as a standby fee and (b) at the Closing, or you may
deduct the same from the above payment for the Shares, an additional amount per
Share purchased (the "Take-up Amount") as follows:  as to the number of Shares
purchased up to 627,557 Shares, 2.75% of the Purchase Price; as to any
additional Shares purchased up to 1,882,673 Shares, 3.75% of the Purchase
Price; as to any additional Shares purchased up to 3,137,789 Shares, 4.75% of
the Purchase Price; and as to any additional Shares purchased, 6.50% of the
Purchase Price; provided, however, that for the purpose of calculating the
Take-Up Amount, the number of Nonresponse Redemption Shares shall be excluded
from the number of Shares so purchased.

              With respect to any Nonresponse Redemption Shares acquired by you
pursuant to this Agreement, you agree to share any profit on resale of such
shares with the Company.  For purposes of this Agreement, the "Adjustment
Amount" equals the aggregate sales price of the Nonresponse Redemption Shares,
less the aggregate purchase price paid by





                                      -7-
<PAGE>   8
the Purchaser in respect of such shares.  Such Adjustment Amount is to be
computed after deduction of selling concessions and commissions, transfer taxes
and your cost of carrying such position (which, for purposes of this Agreement,
shall be deemed to accrue at a rate of 4% per annum).  Upon the completion of
such sales, you shall furnish to the Company a statement setting forth the
sales price or prices for such shares and the applicable selling concessions
and commissions, transfer taxes and cost of carrying.  Nothing contained herein
shall limit your right, in your discretion, to determine the price or prices at
which, and the time or times when, any such shares shall be sold, whether or
not prior to the Redemption Date and whether or not for long or short account.
For the purpose of this paragraph, any Nonresponse Redemption Shares not sold
by you or for your account prior to the close of business on the tenth day
after the Redemption Date shall be deemed to have been sold on such tenth day
for an amount equal to the reported last sale price regular way of the Common
Stock on the New York Stock Exchange Composite Tape on such day.  The
Adjustment Amount shall be allocated 50% to the Purchaser and 50% to the
Company.  Any Adjustment Amount payable by the Purchaser to the Company shall
be paid promptly to the Company.

              SECTION 3.  Covenants.  The Company covenants and agrees with
you:

              (a)    To make no further amendment or any supplement to the
       Registration Statement or Prospectus (other than a document required to
       be filed under the Exchange Act that upon filing is deemed to be
       incorporated by reference therein) prior to the termination of the
       offering of Common Stock by the Purchaser which shall be disapproved by
       you promptly after reasonable notice thereof (which disapproval shall
       not be unreasonable); to advise you promptly of any such amendment or
       supplement and to furnish you with copies thereof; to file promptly all
       reports and any definitive proxy or information statements required to
       be filed by the Company with the Commission pursuant to Section 13(a),
       13(c), 14 or 15(d) of the Exchange Act for so long as the delivery of a
       prospectus is required in connection with the offering or sale of the
       Shares, and during such same period to advise you, promptly after it
       receives notice thereof, of the time when the Registration Statement or
       any amendment to the Registration Statement has been filed or becomes
       effective or any supplement to the Prospectus or any amended Prospectus
       has been filed with the Commission, of the issuance by the Commission of
       any stop order or of any order preventing or suspending the use of any
       prospectus relating to the Shares, of the suspension of the
       qualification of the Shares or any shares of Common Stock for offering
       or sale in any jurisdiction, of the initiation or threatening of any
       proceeding for any such purpose, or of any request by the Commission for
       the amending or supplementing of the Registration Statement or
       Prospectus or for additional information; and, in the events of the
       issuance of any stop order or of any order preventing or suspending the
       use of any prospectus relating to the Shares or suspending any such
       qualification, to use promptly its best efforts to obtain its
       withdrawal.

              (b)    Promptly from time to time to use its best efforts to
       qualify the Shares for offering and sale under the securities laws of
       such jurisdictions as you may reasonably request and to comply with such
       laws so as to permit the continuance of sales and dealings therein in
       such jurisdictions for as long as may be necessary to complete the
       distribution of the Shares, provided that in connection therewith the





                                      -8-
<PAGE>   9
       Company shall not be required to qualify as a foreign corporation or to
       file a general consent to service of process in any jurisdiction.

              (c)    To furnish you, without charge, two signed copies of the
       Registration Statement as originally filed and of each amendment
       thereto, including all exhibits thereto and documents incorporated by
       reference therein, and to furnish you, without charge, such number of
       conformed copies of the Registration Statement as originally filed and
       each amendment thereto, excluding exhibits thereto, and such number of
       the documents incorporated by reference therein, as you may reasonably
       request.

              (d)    To furnish you, without charge, copies of the Prospectus
       in such quantities as you may from time to time reasonably request, and,
       if the delivery of a prospectus is required at any time in connection
       with the offering or sale of the Shares and if at such time any event
       shall have occurred as a result of which the Prospectus would include an
       untrue statement of a material fact or omit to state any material fact
       necessary in order to make the statements therein, in the light of the
       circumstances under which they were made when such prospectus is
       delivered, not misleading, or, if for any other reason it shall be
       necessary during such same period to amend or supplement the Prospectus
       or to file under the Exchange Act any document incorporated by reference
       in the Prospectus in order to comply with the Act or the Exchange Act,
       to notify you and upon your request to file such document and to prepare
       and furnish without charge to you as many copies as you may from time to
       time reasonably request of an amended prospectus or a supplement to the
       prospectus which will correct such statement or omission or effect such
       compliance.

              (e)    To make generally available to its security-holders as
       soon as practicable, but in any event not later than eighteen months
       after the effective date of the Registration Statement (as defined in
       Rule 158(c) of the Act), an earnings statement of the Company and its
       subsidiaries (which need not be audited) complying with Section 11(a) of
       the Act and the rules and regulations of the Commission thereunder
       (including, at the option of the Company, Rule 158), it being understood
       that the Company intends to satisfy this requirement by delivery of its
       annual reports on Form 10-K and its quarterly reports on Form 10-Q.

              (f)    During the period beginning from the date hereof and
       continuing through the Redemption Date, and, if the Purchaser purchases
       any Purchased Shares, further continuing through the date 90 days after
       the Redemption Date, not to offer, sell, contract to sell or otherwise
       dispose of any shares of Common Stock, or any other security convertible
       into or exchangeable for shares of Common Stock (the "Restricted
       Securities"), except for any Restricted Security issued by the Company
       pursuant to its employee benefit plans or shares of Common Stock issued
       or distributed in connection with the conversion of the Notes or any
       other security of the Company outstanding on the date hereof, without
       your prior written consent (such consent not to be unreasonably
       withheld).

              (g)    On the date the Registration Statement becomes effective,
       to mail or cause to be mailed to holders of Notes a Prospectus and a
       notice of redemption (the





                                      -9-
<PAGE>   10
       "Notice of Redemption") of all the Notes on the Redemption Date in
       accordance with the terms of the Indenture, the time of the first such
       mailing being called herein the "Time of Mailing"; and the Company will
       cause notice of redemption to be given by press release at such times as
       you and the Company may mutually agree.

              (h)    To advise you daily or direct the Trustee to advise you
       daily of the respective principal amount of Notes surrendered for
       conversion into Common Stock and surrendered for redemption on the
       preceding day.

              (i)    To supplement the Prospectus, or file a post-effective
       amendment to the Registration Statement, after the Redemption Date to
       set forth the results of the call for redemption and other information
       that may be required to comply with the rules of the Commission, if
       applicable, and, if the Purchaser purchases any Shares hereunder, not
       later than 15 days after the Redemption Date, to file a post-effective
       amendment to the Registration Statement or to take such other steps as
       may be necessary to remove from registration all shares of Common Stock
       which have not been issued to the Purchaser pursuant to Section 2
       hereof.

              SECTION 4.  Payment of Expenses.  The Company covenants and
agrees with you that the Company will pay or cause to be paid the following:
(i) the fees, disbursements and expenses of the Company's counsel and
accountants and all other expenses in connection with the preparation, printing
and filing of the Registration Statement and the Prospectus and amendments and
supplements thereto and the mailing and delivering of copies thereof; (ii) the
costs of any filing with the National Association of Securities Dealers, Inc.,
if required; (iii) all costs and expenses, including printing expenses, in
connection with the preparation and mailing of the Notice of Redemption and
related documents and the publication of any advertisement relating to the
redemption of the Notes; (iv) all costs and expenses in connection with the
issuance and delivery of shares of Common Stock upon conversion of the Notes,
including transfer taxes, if any, and the fees and expenses of the Trustee, and
as otherwise contemplated by this Agreement; (v) the cost of printing or
producing this Agreement, any Blue Sky Memorandum or survey and any other
documents in connection with the offering, purchase, sale and delivery of the
Shares; (vi) all expenses in connection with the qualification of the shares
for offering and sale under state securities laws as provided in Section 3(b)
hereof, including filing fees and the reasonable fees and disbursements of
counsel for the Purchaser in connection with such qualification and in
connection with any Blue Sky Memorandum or survey; (vii) the cost of preparing
the Shares; (viii) all reasonable out-of-pocket expenses of the Purchaser
(other than any selling concessions and commissions) and fees, disbursements
and expenses of counsel for the Purchaser in connection with this Agreement and
the transactions contemplated hereby; and (ix) all other costs and expenses
incident to the performance of its obligations hereunder which are not
otherwise specifically provided for in this Section.

              You agree that in the event the Trustee should require from the
Company any deposit of funds pursuant to Section 1106 of the Indenture, you
shall advance such funds to the Company and deposit such funds with the Trustee
on behalf of the Company (such advance and deposit a "Trustee Deposit").  The
Company agrees to repay or to cause the Trustee to repay to you any such
Trustee Deposit as soon as the Trustee no longer requires





                                      -10-
<PAGE>   11
such funds to be deposited with it pursuant to Section 1106 of the Indenture.
The Company agrees further to reimburse you on the Closing Date in an amount
equal to your cost of funds on any such Trustee Deposit from the date of such
deposit through the Closing Date.

              SECTION 5.  Conditions of Purchaser's Obligations.  Your
obligations hereunder shall be subject, in your discretion, to the condition
that all representations and warranties of the Company herein are, at and as of
the date hereof and the date of the Closing (as if made on and as of such
dates), true and correct, the condition that the Company shall have performed
all of its obligations hereunder theretofore to be performed in all material
respects, and the following additional conditions, it being understood,
however, that the representation and warranty in Section 1(e) and the condition
in Section 5(g) shall extend only to the Time of Mailing:

              (a)  The Registration Statement shall have become effective not
       later than 5:30 P.M., New York City time, on the date hereof.

              (b)  On the date the Registration Statement becomes effective
       (prior to the mailing of the Notice of Redemption) and on the Closing
       Date you shall have received:

              (1)    The written opinion of Thompson & Knight, P.C., counsel
       for the Company, dated the date the Registration Statement becomes
       effective and the Closing Date, respectively, substantially to the
       effect that:

                     (i)  The Company and each of Noble Gas Marketing, Inc.,
              Noble Trading, Inc., Samedan Oil Corporation and Energy
              Development Corporation ("EDC") (each, a Material Subsidiary) has
              been duly incorporated and is an existing corporation in good
              standing under the laws of its jurisdiction of incorporation and
              has full corporate power and authority to conduct its business as
              described in the Registration Statement and Prospectus; and all
              of the outstanding shares of capital stock of each Material
              Subsidiary have been duly authorized and validly issued, are
              fully paid and non-assessable and (except as otherwise stated in
              the Registration Statement) are owned beneficially by the Company
              subject to no security interest or other encumbrance or claim
              affecting transferability or voting;

                     (ii)  The Notes are convertible into Common Stock of the
              Company in accordance with the terms of the Indenture; and the
              shares of such Common Stock initially issuable upon conversion of
              the Notes have been duly authorized and reserved for issuance
              upon such conversion, and, when so issued and delivered against
              payment therefor in accordance with the Indenture, will be
              validly issued, fully paid and non-assessable; all of the
              outstanding shares of Common Stock of the Company have been duly
              authorized and validly issued, are fully paid, non-assessable and
              not subject to any preemptive or similar right; the authorized
              and outstanding capital stock of the Company is as set forth in
              the Registration Statement and the Prospectus under the heading
              "Capitalization"; the description of the Common





                                      -11-
<PAGE>   12
              Stock contained in the Prospectus under the heading "Description
              of Capital Stock" conforms to the terms thereof contained in the
              Company's certificate of incorporation; and the shareholders of
              the Company have no preemptive rights with respect to the Shares
              under the Company's certificate of incorporation or bylaws or
              applicable state law;

                     (iii)  The Registration Statement has become effective
              under the Act; and to the best knowledge of such counsel no stop
              order suspending the effectiveness of the Registration Statement
              has been issued and no proceeding for that purpose has been
              instituted or threatened by the Commission;

                     (iv)  Each part of the Registration Statement, when such
              part became effective, and the Prospectus and any amendment or
              supplement thereto, on the date of filing thereof with the
              Commission, complied as to form in all material respects with the
              requirements of the Act and the rules and regulations of the
              Commission thereunder; and the documents incorporated by
              reference in the Registration Statement or Prospectus or any
              amendment or supplement thereto, when they became effective under
              the Act or were filed with the Commission under the Exchange Act,
              as the case may be, complied as to form in all material respects
              with the requirements of the Act or the Exchange Act, as
              applicable, and the rules and regulations of the Commission
              thereunder; it being understood that such counsel need express no
              opinion as to the financial statements, schedules and other
              financial data included in any of the documents mentioned in this
              clause;

                     (v)  The description of the Credit Agreement dated as of
              July 31, 1996 among the Company, as borrower, certain commercial
              lending institutions which are or may become a party thereto, as
              lenders, and Union Bank of Switzerland, as agent for the lenders,
              contained under "Acquisition or Disposition of Assets" in the
              Company's Form 8-K (Date of Event: July 31, 1996), as amended, is
              accurate in all material respects; and such counsel do not know
              of any legal or governmental proceedings required to be described
              in the Prospectus that are not described as required, or of any
              contracts or documents of a character required to be described in
              the Registration Statement or Prospectus (or required to be filed
              under the Exchange Act if upon such filing they would be
              incorporated by reference therein) or to be filed as exhibits to
              the Registration Statement that are not described or filed as
              required;

                     (vi)  This Agreement has been duly authorized, executed
              and delivered by the Company; the performance of this Agreement
              and the consummation of the transactions herein contemplated by
              the Company will not result in a breach or violation of any of
              the terms and provisions of, or constitute a default under, any
              statute, any material agreement or instrument known to such
              counsel to which the Company is a party or by which it is bound
              or to which any of the property of the Company is subject, the
              Company's certificate of incorporation or by-laws, or any order,
              rule or regulation known





                                      -12-
<PAGE>   13
              to such counsel to be applicable to the Company or any subsidiary
              thereof of any court or governmental agency or body having
              jurisdiction over the Company or any of its properties; and no
              consent, approval, authorization or order of, or filing with, any
              court or governmental agency or body is required for the
              consummation by the Company of the transactions contemplated by
              this Agreement in connection with the issuance or sale of the
              Shares by the Company, except such as have been obtained under
              the Act and such as may be required under state securities laws
              in connection with the purchase and distribution of the Shares by
              the Purchaser;

                     (vii)  The statements in the Prospectus under the caption
              "Description of Capital Stock", insofar as such statements
              constitute summaries of the documents and legal matters referred
              to therein, fairly summarize such documents and matters; and

                     (viii)  The redemption of all of the outstanding Notes on
              the Redemption Date has been duly authorized; and the only
              remaining action required by the terms of the Notes or the
              Indenture to call the Notes for redemption on the Redemption Date
              is the giving of the notice of redemption by mail in accordance
              with the provisions of the Indenture.

                     The foregoing opinions may be limited to the General
              Corporation Law of the State of Delaware, the laws of the State
              of Texas, the New Jersey Business Corporation Act, the laws of
              the State of New York and applicable federal law.  In rendering
              the foregoing opinions, counsel may rely, to the extent they deem
              such reliance proper, on the opinions (in form and substance
              reasonably satisfactory to the Purchaser) of other counsel
              reasonably acceptable to the Purchaser as to matters governed by
              the laws of jurisdictions other than the United States, the State
              of Texas, and the General Corporation Law of the State of
              Delaware, and as to matters of fact, upon certificates of
              officers of the Company and of government officials.  Copies of
              all such opinions and certificates shall be furnished to counsel
              to the Purchaser on the date the Registration Statement becomes
              effective and on the Closing Date.

                     Concurrently with the delivery of its opinion, Thompson &
              Knight, P.C., shall advise the Purchaser in writing that, in the
              course of its representation of the Company in connection with
              the preparation of the Registration Statement and Prospectus,
              nothing has come to its attention that gives it any reason to
              believe either that any part of the Registration Statement, when
              such part became effective, contained an untrue statement of a
              material fact or omitted to state a material fact required to be
              stated therein or necessary to make the statements therein not
              misleading or that the Prospectus and any amendment or supplement
              thereto, as of its date or (if applicable) as of the Closing
              Date, included an untrue statement of a material fact or omitted
              to state a material fact necessary to make the statements
              therein, in the light of the circumstances under which they were
              made, not misleading.





                                      -13-
<PAGE>   14
              (2)  The written opinion or opinions of Sullivan & Cromwell,
       counsel for the Purchaser, dated the date the Registration Statement
       becomes effective and the Closing Date, respectively, with respect to
       the incorporation of the Company, the validity of the Shares, the
       Registration Statement, the Prospectus and other related matters as you
       may reasonably request, and such counsel shall have received such papers
       and information as they may reasonably request to enable them to pass
       upon such matters.

              (c)  No stop order suspending the effectiveness of the
       Registration Statement or any part thereof shall have been issued and no
       proceeding for that purpose shall have been initiated or threatened by
       the Commission, nor shall there have been any injunction, restraining
       order or other order of a court or any governmental agency which
       prohibits or restrains the Purchaser from converting the Notes into
       Common Stock.

              (d)  There shall not have been any change after the date of this
       Agreement in the charter or by-laws of the Company adversely affecting
       the rights of the holders of the Common Stock.

              (e)  On the effective date of the Registration Statement (prior
       to the mailing of the Notice of Redemption), and on the Closing Date,
       respectively, you shall have received a letter from Arthur Andersen LLP,
       dated the date of delivery thereof, to the effect that (i) they are
       independent certified public accountants with respect to the Company
       within the meaning of the Act and the rules and regulations of the
       Commission thereunder; (ii) in their opinion, the financial statements
       audited by them included or incorporated by reference in the
       Registration Statement and Prospectus comply as to form in all material
       respects with the applicable requirements of the Act and the Exchange
       Act and the related published rules and regulations thereunder; (iii)
       nothing came to their attention as a result of performing certain
       specified procedures that caused them to believe that the unaudited pro
       forma consolidated condensed financial statements included or
       incorporated by reference in the Registration Statement do not comply as
       to form in all material respects with the applicable accounting
       requirements of Rule 11-02 of Regulation S-X or that the pro forma
       adjustments have not been properly applied to the historical amounts in
       the compilation of those statements; and (iv) as to such other matters
       relating to such financial statements and financial information as you
       may reasonably request and in form and substance satisfactory to you.

              (f)  On the effective date of the Registration Statement (prior
       to the mailing of the Notice of Redemption), and on the Closing Date,
       respectively, you shall have received a letter from Deloitte & Touche
       LLP, dated the date of delivery thereof, to the effect that (i) they are
       independent certified public accountants with respect to each of EDC and
       the Company within the meaning of the Act and the applicable published
       rules and regulations thereunder; and (ii) in their opinion, the
       financial statements in respect of EDC audited by them and incorporated
       by reference in the Registration Statement comply as to form in all
       material respects with the applicable requirements of the Act or the
       Exchange Act, as applicable, and the published rules and regulations
       thereunder.





                                      -14-
<PAGE>   15
              (g)  (i) Neither the Company nor any of its subsidiaries shall
       have sustained since the date of the latest audited financial statements
       included or incorporated by reference in the Prospectus and prior to the
       Time of Mailing any loss or interference with its business from fire,
       explosion, flood or other calamity, or from any labor dispute or court
       or governmental action, order or decree, otherwise than as set forth or
       contemplated in the Prospectus (or indicated in the financial statements
       included or incorporated by reference therein), and (ii) since the
       respective dates as of which information is given in the Prospectus and
       prior to the Time of Mailing there shall not have been any change on a
       consolidated basis in the capital stock, short-term debt or long-term
       debt of the Company and its subsidiaries or any change, or any
       development involving a prospective change, in or affecting the general
       affairs, management, financial position, shareholders' equity or results
       of operations of the Company and its subsidiaries, otherwise than as set
       forth or contemplated in the Prospectus, the effect of which, in any
       such case described in clause (i) or (ii), in your judgment, taking into
       account your prior knowledge of the Company and the industry in which
       the Company operates, so materially and adversely affects the business,
       financial condition or results of operations of the Company and its
       subsidiaries (taken as a whole) as to make it impracticable to complete
       the public offering or the delivery of the Shares on the terms and in
       the manner contemplated in the Prospectus.

              (h)  On or after the date hereof there shall not have occurred
       any of the following:  (i) a suspension or limitation in trading in
       securities generally on the New York Stock Exchange; (ii) a suspension
       or material limitation in trading in the Company's shares of Common
       Stock on the New York Stock Exchange, the effect of which in your
       reasonable judgment makes it impracticable to complete the public
       offering or the delivery of the Shares on the terms and in the manner
       contemplated by the Prospectus; (iii) a general moratorium on commercial
       banking activities in New York declared by either Federal or New York
       State authorities; (iv) a material adverse change in the condition,
       financial or otherwise, earnings, business or prospects of the Company
       and its subsidiaries considered as a whole, whether or not arising in
       the ordinary course of business; (v) the outbreak or escalation of
       hostilities involving the United States or the declaration by the United
       States of a national emergency or war; or (vi) a substantial national or
       international calamity or other occurrence of a material adverse change
       in general economic, political or financial conditions in the United
       States, or internationally having a material impact on such conditions
       in the United States, if the effect of any such event specified in
       clause (iv), (v) or (vi) in your judgment makes it impracticable to
       complete the public offering or the delivery of the Shares on the terms
       and in the manner contemplated by the Prospectus.

              (i)  On the effective date of the Registration Statement (prior
       to the mailing of the Notice of Redemption) and also on the Closing
       Date, the Company shall have furnished or caused to be furnished to you
       a certificate or certificates, dated the effective date of the
       Registration Statement and the Closing Date, respectively, of officers
       of the Company satisfactory to you as to the accuracy of the
       representations and warranties of the Company herein at and as of the
       date of such certificate or certificates, as to the performance in all
       material respects by the Company of all of its





                                      -15-
<PAGE>   16
       obligations hereunder to be performed at or prior to the time such
       certificate or certificates shall be furnished to you, as to the matters
       set forth in subsections (a), (c) and (g) of this Section and as to such
       other matters as you may reasonably request, it being understood,
       however, that the representation and warranty in Section 1(e) and the
       condition in Section 5(g) shall extend only to the Time of Mailing.

              If any condition specified in this Section 5 shall not have been
fulfilled when and as required by this Agreement to be fulfilled, this
Agreement and all your obligations hereunder may be canceled by you by
notifying the Company of such cancellation in writing or by telegram at any
time at or prior to the Redemption Date, and any such cancellation shall be
without liability of any party to any other party except as provided in Section
4, Section 7 and Section 9(c).  Opinions and letters received without objection
by the Purchaser on the effective date of the Registration Statement or on the
Closing Date, as applicable, shall thereafter be deemed to have fulfilled that
portion of this Agreement requiring the delivery of such opinions or letters
when and as required by this Agreement.

              SECTION 6.  Additional Purchases.  Until 5:00 p.m., New York City
time, on the Redemption Date, you may (but shall be under no obligation to)
purchase Notes in such amounts and at such prices as you may deem advisable.
The Common Stock acquired by you on conversion of the Notes purchased by you
pursuant to this Section may be sold at any time or from time to time by you.
It is also understood that, for the purpose of stabilizing the price of the
Common Stock or otherwise, you may make purchases and sales of Common Stock or
Notes, in the open market or otherwise, for long or short account, on such
terms as you deem advisable, and may over-allot in arranging sales, all subject
to applicable provisions of the Exchange Act and the rules and regulations of
the Commission thereunder.

              Subject to the conditions set forth in Section 5 hereof, in the
event that Notes to be delivered to the Trustee to be converted into shares of
Common Stock pursuant to the guaranteed delivery procedures described in the
Notice of Redemption are not so delivered by the close of business on the tenth
business day following the Redemption Date, you agree to purchase on the next
succeeding business day shares of Common Stock (the "Failed Shares") equal in
number to the number of shares of Common Stock which would have been delivered
upon conversion of such Notes at a price per share equal to the Purchase Price.
At 9:30 a.m., New York City time, on the eleventh business day following the
Redemption Date, you agree to pay to the Company, by wire transfer in
immediately available funds, the aggregate Purchase Price for the Failed
Shares, and the Company agrees simultaneously to deliver to you certificates
evidencing the Failed Shares (in definitive form and registered in such names
and in such denominations as you shall request by written notice to the
Company).  The Company shall pay the Purchaser an amount per Failed Share by
wire transfer in immediately available funds equal to the highest Take-up
Amount per Purchased Share paid by the Company to the Purchaser at the Closing.
Delivery of the certificates evidencing the Failed Shares shall be made in
accordance with Section 2 hereof.

              SECTION 7.  Indemnification.  (a)  The Company will indemnify you
and hold you harmless against any losses, claims, damages or liabilities to
which you may become subject, under the Act or otherwise, insofar as such
losses, claims, damages or liabilities (or actions in respect thereof) arise
out of or are based upon an untrue statement or alleged untrue





                                      -16-
<PAGE>   17
statement of a material fact contained in the Registration Statement, the
Prospectus and any other prospectus relating to the Shares, or any amendment or
supplement thereto, or arise out of or are based upon the omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, and will reimburse you
for any legal or other expenses reasonably incurred by you in connection with
investigating or defending any such action or claim as such expenses are
incurred; provided, however, that the Company shall not be liable in any such
case to the extent that any such loss, claim, damage or liability arises out of
or is based upon an untrue statement or alleged untrue statement or omission or
alleged omission made in the Registration Statement, the Prospectus and any
other prospectus relating to the Shares, or any such amendment or supplement,
in reliance upon and in conformity with written information furnished to the
Company by you expressly for use in the Prospectus.

              (b)  You will indemnify and hold harmless the Company against any
losses, claims, damages or liabilities to which the Company may become subject,
under the Act or otherwise, insofar as such losses, claims, damages or
liabilities (or actions in respect thereof) arise out of or are based upon an
untrue statement or alleged untrue statement of a material fact contained in
the Registration Statement, the Prospectus and any other prospectus relating to
the Shares, or any amendment or supplement thereto, or arise out of or are
based upon the omission or alleged omission to state therein a material fact
required to be stated therein or necessary to make the statements therein not
misleading, in each case to the extent, but only to the extent, that such
untrue statement or alleged untrue statement or omission or alleged omission
was made in the Registration Statement, the Prospectus and any other prospectus
relating to the Shares, or any such amendment or supplement, in reliance upon
and in conformity with written information furnished to the Company by you
expressly for use therein; and will reimburse the Company for any legal or
other expenses reasonably incurred by the Company in connection with
investigating or defending any such action or claim as such expenses are
incurred.

              (c)  Promptly after receipt by an indemnified party under
subsection (a) or (b) above of notice of the commencement of any action, such
indemnified party shall, if a claim in respect thereof is to be made against
the indemnifying party under such subsection, notify the indemnifying party in
writing of the commencement thereof; but the omission so to notify the
indemnifying party shall not relieve it from any liability which it may have to
any indemnified party otherwise than under such subsection.  In case any such
action shall be brought against any indemnified party and it shall notify the
indemnifying party of the commencement thereof, the indemnifying party shall be
entitled to participate therein and, to the extent that it shall wish, to
assume the defense thereof, with counsel satisfactory to such indemnified party
(who shall not, except with the consent of the indemnified party, be counsel to
the indemnifying party), and, after notice from the indemnifying party to such
indemnified party of its election so to assume the defense thereof, the
indemnifying party shall not be liable to such indemnified party under such
subsection for any legal expenses of other counsel or any other expenses, in
each case subsequently incurred by such indemnified party, in connection with
the defense thereof other than reasonable costs of investigation.

              (d)  If the indemnification provided for in this Section 7 is
unavailable to or insufficient to hold harmless an indemnified party under
subsection (a) or (b) above in respect





                                      -17-
<PAGE>   18
of any losses, claims, damages or liabilities (or actions in respect thereof)
as contemplated therein, then each indemnifying party shall contribute to the
amount paid or payable by such indemnified party as a result of such losses,
claims, damages or liabilities (or actions in respect thereof) in such
proportion as is appropriate to reflect the relative benefits received by the
Company on the one hand and you on the other from the offering of the Shares to
which such loss, claim, damage or liability (or action in respect thereof)
relates.  If, however, the allocation provided by the immediately preceding
sentence is not permitted by applicable law or if the indemnified party failed
to give the notice required under subsection (c) above, then each indemnifying
party shall contribute to such amount paid or payable by such indemnified party
in such proportion as is appropriate to reflect not only such relative benefits
but also the relative fault of the Company on the one hand and you on the other
in connection with the statements or omissions which resulted in such losses,
claims, damages or liabilities (or actions in respect thereof), as well as any
other relevant equitable considerations.  The relative benefits received by the
Company on the one hand and you on the other shall be deemed to be in the same
proportion as the aggregate price of the Shares received by the Company bears
to the aggregate Take-up Amount for such Shares received by you pursuant to
this Agreement.  The relative fault shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by the Company on the one hand or you on the other and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission.  The Company and you agree that
it would not be just and equitable if contribution pursuant to this subsection
(d) were determined by pro rata allocation or by any other method of allocation
which does not take account of the equitable considerations referred to above
in this subsection (d).  The amount paid or payable by an indemnified party as
a result of the losses, claims, damages or liabilities (or actions in respect
thereof) referred to above in this subsection (d) shall be deemed to include
any legal or other expenses reasonably incurred by such indemnified party in
connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this subsection (d), you shall not be
required to contribute any amount in excess of the amount by which the total
price of the Shares purchased by you from the Company pursuant to Section 2 of
this Agreement and distributed to the public exceeds the amount of any damages
which you have otherwise been required to pay by reason of such untrue or
alleged untrue statement or omission or alleged omission.  No person guilty of
fraudulent misrepresentation (within the meaning of Section 11(f) of the Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.

              (e)  The obligations of the Company under this Section 7 shall be
in addition to any liability which the Company may otherwise have and shall
extend, upon the same terms and conditions, to each person, if any, who
controls you within the meaning of the Act; and your obligations under this
Section 7 shall be in addition to any liability which you may otherwise have
and shall extend, upon the same terms and conditions, to each officer and
director of the Company and to each person, if any, who controls the Company
within the meaning of the Act.

              SECTION 8.  Indemnities, Agreements, Representations and
Warranties to Survive.  The respective indemnities, agreements,
representations, warranties and other statements of the Company and you, as set
forth in this Agreement, or as set forth by the





                                      -18-
<PAGE>   19
Company in certificates of officers of the Company furnished to you pursuant to
this Agreement, shall remain in full force and effect, regardless of any
investigation (or any statement as to the results thereof) made by or on behalf
of you or any person who controls you, or the Company, or any officer or
director or controlling person of the Company, and shall survive delivery of
and payment for the Shares.

              SECTION 9.  Effectiveness and Termination of Agreement.  (a)
This Agreement shall become effective only upon receipt by you and the Company
of notification of the effectiveness of the Registration Statement, unless
prior to such time the Company shall have given notice to you or you shall have
given notice to the Company that this Agreement shall not become effective.
Any such notice shall be effective only upon receipt.

              (b)  Prior to the time the Company commences the mailing to
holders of Notes of notices that the Notes is to be redeemed on the Redemption
Date, this Agreement may be terminated by the Company by notice to you, or by
you by notice to the Company.  Any such notice shall be effective only upon
receipt.

              (c)  If this Agreement shall be terminated pursuant to this
Section or Section 5, the Company shall not be under any liability to you
except as provided in Section 2, Section 4, Section 7 and Section 8 hereof and
except that the Company will reimburse you for all reasonable out-of-pocket
expenses incurred by you, including reasonable fees, disbursements and expenses
of counsel, in making preparations for the purchase, sale and delivery of the
Shares.

              SECTION 10.  Notices.  Except as herein otherwise provided, all
statements, requests, notices and agreements hereunder shall be in writing, and
if to you shall be delivered or sent by mail, telex or facsimile transmission
to you at 299 Park Avenue, New York, New York 10171, Attention:  Richard
Messina; and if to the Company shall be delivered or sent by mail, telex or
facsimile transmission to it at 110 West Broadway, Ardmore, Oklahoma 73401,
Attention:  Robert Kelley, President and Chief Executive Officer.  Any such
statements, requests, notices or agreements shall take effect upon receipt
thereof.

              SECTION 11.  Parties.  This Agreement shall be binding upon, and
inure solely to the benefit of, you, the  Company and, to the extent provided
in Section 7 and Section 8 hereof, the officers and directors of the Company
and each person who controls the Company or you, and their respective heirs,
executors, administrators, successors and assigns, and no other person shall
acquire or have any right under or by virtue of this Agreement.  No purchaser
of any of the Shares from you shall be deemed a successor or assign by reason
merely of such purchase.

              SECTION 12.  Time shall be of the essence of this Agreement.

              SECTION 13.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.





                                      -19-
<PAGE>   20
              SECTION 14.  This Agreement may be executed by any one or more of
the parties hereto in any number of counterparts, each of which shall be deemed
to be an original, but all such respective counterparts shall together
constitute one and the same instrument.

              If the foregoing is in accordance with your understanding, please
sign and return to us three counterparts hereof, and, upon the acceptance
hereof by you, this letter and such acceptance hereof shall constitute a
binding agreement between you and the Company.

                                   Very truly yours,

                                   NOBLE AFFILIATES, INC.



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


Accepted as of the date hereof:

UBS SECURITIES LLC



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





                                      -20-

<PAGE>   1
                                                                     EXHIBIT 4.2





                      FIRST AMENDMENT TO CREDIT AGREEMENT


                          dated as of October 15, 1996


                                     among


                            NOBLE AFFILIATES, INC.,
                                as the Borrower,


                                      and


                           UNION BANK OF SWITZERLAND
                                Houston Agency,
                          as the Agent for the Lenders


                                      and


                         NATIONSBANK OF TEXAS, N.A. and
                   TEXAS COMMERCE BANK NATIONAL ASSOCIATION,
                               as Managing Agents


                                      and


                               BANK OF MONTREAL,
                                   CIBC INC.,
                      THE FIRST NATIONAL BANK OF CHICAGO,
                           ROYAL BANK OF CANADA, and
                      SOCIETE GENERALE, SOUTHWEST AGENCY,
                                  as Co-Agents


                                      and
<PAGE>   2
                    CERTAIN COMMERCIAL LENDING INSTITUTIONS,
                                 as the Lenders
<PAGE>   3
                      FIRST AMENDMENT TO CREDIT AGREEMENT


       THIS FIRST AMENDMENT TO CREDIT AGREEMENT, dated as of October 15, 1996
(as may be amended, restated, supplemented or otherwise modified from time to
time, this "First Amendment"), is entered into by and among NOBLE AFFILIATES,
INC., a Delaware corporation (the "Borrower"), UNION BANK OF SWITZERLAND,
Houston Agency ("UBS"), as administrative agent (UBS in such capacity, together
with any successor(s) thereto in such capacity, the "Agent"), NATIONSBANK OF
TEXAS, N.A.  ("NB") and TEXAS COMMERCE BANK NATIONAL ASSOCIATION ("TCB"), as
managing agents (NB and TCB in such capacities, together with any successor(s)
thereto in such capacities, collectively called the "Managing Agents"), BANK OF
MONTREAL ("BOM"), CIBC INC. ("CIBC"), THE FIRST NATIONAL BANK OF CHICAGO
("First Chicago"), ROYAL BANK OF CANADA ("RBC") and SOCIETE GENERALE, SOUTHWEST
AGENCY ("SocGen"), as co-agents (BOM, CIBC, First Chicago, RBC and SocGen in
such capacities, together with any successor(s) thereto in such capacities,
collectively called the "Co-Agents"), and certain commercial lending
institutions as are or may become parties hereto (collectively, the "Lenders").

                              W I T N E S S E T H:

       WHEREAS, the Borrower and UBS (both individually as a Lender and as the
Agent thereunder) have heretofore entered into that certain Credit Agreement,
dated as of July 31, 1996 (the "Credit Agreement"); and

       WHEREAS, the Borrower, the Lenders, the Agent, the Managing Agents and
the Co-Agents now intend to amend the Credit Agreement in certain respects.

       NOW, THEREFORE, in consideration of the premises and of the mutual
covenants herein contained, each of the Borrower, the Lenders, the Agent, the
Managing Agents and the Co-Agents agree as follows:

       SECTION 1.    Defined Terms.  Terms defined in the Credit Agreement are
used in this First Amendment with the same meaning, unless otherwise indicated.

       SECTION 2.    Amendments to Credit Agreement.

       A.     The preamble of the Credit Agreement is hereby amended in its
entirety to read as follows:

              "THIS CREDIT AGREEMENT, dated as of July 31. 1996 (as may be
       amended, restated, supplemented or otherwise modified from time to time,
       this "Agreement"), is among NOBLE AFFILIATES, INC., a Delaware
       corporation (the "Borrower"), UNION
<PAGE>   4
       BANK OF SWITZERLAND, Houston Agency ("UBS"), as administrative agent
       (UBS in such capacity, together with any successor(s) thereto in such
       capacity, the "Agent"), NATIONSBANK OF TEXAS, N.A. ("NB") and TEXAS
       COMMERCE BANK NATIONAL ASSOCIATION ("TCB"), as managing agents (NB and
       TCB in such capacities, together with any successor(s) thereto in such
       capacities, collectively called the "Managing Agents"), BANK OF MONTREAL
       ("BOM"), CIBC INC.  ("CIBC"), THE FIRST NATIONAL BANK OF CHICAGO ("First
       Chicago"), ROYAL BANK OF CANADA ("RBC") and SOCIETE GENERALE, SOUTHWEST
       AGENCY ("SocGen"), as co-agents (BOM, CIBC, First Chicago, RBC and
       SocGen in such capacities, together with any successor(s) thereto in
       such capacities, collectively called the "Co-Agents"), and certain
       commercial lending institutions as are or may become parties hereto
       (collectively, the "Lenders")."

       All descriptive references to the Credit Agreement contained in the
Exhibits and cover page to the Credit Agreement are hereby understood to be
appropriately amended so as to mirror, as closely as the context may allow, the
immediately preceding descriptive language.

       B.     Section 1.1 of the Credit Agreement is amended by adding the
following definitions in the appropriate alphabetical order:

              "Co-Agents" is defined in the preamble.

              "First Amendment" means that certain First Amendment to Credit
       Agreement dated as of October 15, 1996 by and among the Borrower, the
       Lenders, the Agent, the Managing Agents and the Co-Agents, as may be
       amended, supplemented, restated or otherwise modified from time to time.

              "Managing Agents" is defined in the preamble.

       C.     The following definitions appearing in Section 1.1 of the Credit
Agreement are hereby amended and restated in their entirety as follows:

              "Lenders" means the financial institutions listed on the
       signature pages of the First Amendment and their respective successors
       and assigns in accordance with Section 10.11 of the Credit Agreement
       (including any commercial lending institution becoming a party hereto
       pursuant to a Lender Assignment Agreement) or otherwise by operation of
       law.

              "Percentage" means, relative to any Lender, the percentage set
       forth opposite the name of such Lender in Exhibit B of the First
       Amendment as such percentage may be adjusted from time to time pursuant
       to Lender Assignment Agreements executed by a Lender and its Assignee
       Lenders and delivered pursuant to Section 10.11.





                                       2
<PAGE>   5
       D.     Section 3.1(b)(ii) is amended in its entirety to read as follows:

              "(ii)  the net cash proceeds from the issuance by the Borrower or
       any of its Subsidiaries of any common stock or preferred stock (other
       than stock issued by a Subsidiary of the Borrower to the Borrower or a
       wholly- owned Subsidiary of the Borrower and other than sales of stock
       to officers, directors or employees pursuant to a stock option plan or
       otherwise), to the extent that the proceeds of any such issuance of
       common stock or preferred stock of the Borrower are not used to repay
       all or any portion of the Borrower's 4 1/4% Convertible Subordinated
       Notes due 2003; and"

       E.     The proviso at the end of Section 3.1(c) of the Credit Agreement
following clause (c)(iii) is amended in its entirety to read as follows:

              "provided, however, that if on or before December 31, 1996, at
       least $200,000,000 in the aggregate principal amount of the Borrower's 4
       1/4% Convertible Subordinated Notes due 2003 shall have been converted
       into, exchanged for or repaid with proceeds from the issuance of shares
       of common stock or preferred stock of the Borrower, then (1) the dollar
       amounts in the foregoing clauses (c)(i),(ii) and (iii) shall be replaced
       with $0, $50,000,000 and $100,000,000, respectively, and (2) as of June
       30, 1998, the Borrower shall in addition to any prepayments pursuant to
       clause (b), make a prepayment on the Term Facility in an amount equal to
       the positive difference, if any, of $150,000,000 minus the sum of (A)
       all prepayments made on or prior to such date pursuant to the foregoing
       clauses (a) and (b)(ii) plus (B) the mandatory prepayments, if any, made
       pursuant to the foregoing clauses (c)(i), (ii) and (iii)."

       F.     Article IX of the Credit Agreement is hereby amended in its
entirety to read as follows:

       "                         ARTICLE IX

                THE AGENT, THE MANAGING AGENTS AND THE CO-AGENTS

       SECTION 9.1   Actions.  Each Lender hereby (i) appoints UBS as the Agent
under this Agreement, the Notes and each other Loan Document, (ii) acknowledges
each of NB and TCB as a Managing Agent under this Agreement, the Notes and each
other Loan Document, and (iii) acknowledges each of BOM, CIBC, First Chicago,
RBC and SocGen as a Co-Agent under this Agreement, the Notes and each other
Loan Document.  Each Lender authorizes the Agent to act on behalf of such
Lender under this Agreement, the Notes and each other Loan Document and, in the
absence of other written instructions from the Required Lenders received from
time to time by the Agent (with respect to which the Agent agrees that it will
comply, except as otherwise provided in this Section or as otherwise advised by
counsel), to exercise such powers hereunder and thereunder as are specifically
delegated to or required of the Agent by the terms





                                       3
<PAGE>   6
hereof and thereof, together with such powers as may be reasonably incidental
thereto.  Each Lender acknowledges that none of the Managing Agents and the
Co-Agents have any duties or obligations under this Agreement in connection
with their capacity as a Managing Agent or a Co-Agent, as the case may be.
Each Lender hereby indemnifies (which indemnity shall survive any termination
of this Agreement) each of the Agent, the Managing Agents and the Co-Agents,
pro rata according to such Lender's Percentage, whether or not related to any
singular, joint or concurrent negligence of the Agent, the Managing Agents and
the Co-Agents, from and against any and all liabilities, obligations, losses,
damages, claims, costs or expenses of any kind or nature whatsoever which may
at any time be imposed on, incurred by, or asserted against, the Agent, any
Managing Agent or any Co-Agent in any way relating to or arising out of this
Agreement, the Notes and any other Loan Document, including reasonable
attorneys' fees, and as to which the Agent, such Managing Agent or such
Co-Agent is not reimbursed by the Borrower; provided, however, that no Lender
shall be liable for the payment of any portion of such liabilities,
obligations, losses, damages, claims, costs or expenses which are determined by
a court of competent jurisdiction in a final proceeding to have resulted solely
from the Agent's, such Managing Agent's or such Co-Agent's gross negligence or
wilful misconduct.  None of the Agent, the Managing Agents and the Co-Agents
shall be required to take any action hereunder, under the Notes or under any
other Loan Document, or to prosecute or defend any suit in respect of this
Agreement, the Notes or any other Loan Document, unless it is indemnified
hereunder to its satisfaction.  If any indemnity in favor of the Agent, any
Managing Agent or any Co-Agent shall be or become inadequate, in the Agent's,
such Managing Agent's or such Co-Agent's determination, as the case may be, the
Agent, such Managing Agent or such Co-Agent, as the case may be, may call for
additional indemnification from the Lenders and cease to do the acts
indemnified against hereunder until such additional indemnity is given.
Notwithstanding any provision to the contrary contained elsewhere in this
Agreement or in any other Loan Document, none of the Agent, the Managing Agents
and the Co-Agents shall have any duties or responsibilities, except as
expressly set forth herein, nor shall any of the Agent, the Managing Agents and
the Co-Agents have or be deemed to have any fiduciary relationship with any
Lender, and no implied covenants, functions, responsibilities, duties,
obligations or liabilities shall be read into this Agreement or any other Loan
Document or otherwise exist against any of the Agent, the Managing Agents and
the Co-Agents.

       SECTION 9.2   Funding Reliance, etc.  Unless the Agent shall have been
notified by telephone, confirmed in writing, by any Lender by 5:00 p.m., New
York time, on the day prior to a Borrowing that such Lender will not make
available the amount which would constitute its Percentage of such Borrowing on
the date specified therefor, the Agent may assume that such Lender has made
such amount available to the Agent and, in reliance upon such assumption, make
available to the Borrower a corresponding amount.  If and to the extent that
such Lender shall not have made such amount available to the Agent, such Lender
and the Borrower severally agree to repay the Agent forthwith on demand such
corresponding amount together with interest thereon, for each day from the date
the Agent made such amount available to the Borrower to the date such amount is
repaid to the Agent, at the Federal Funds Rate.





                                       4
<PAGE>   7
       SECTION 9.3   Exculpation.  None of the Agent, the Managing Agents, the
Co-Agents and their respective directors, officers, employees or agents shall
be liable to any Lender for any action taken or omitted to be taken by it under
this Agreement or any other Loan Document, or in connection herewith or
therewith, except for its own wilful misconduct or gross negligence, nor
responsible for any recitals or warranties herein or therein, nor for the
effectiveness, enforceability, validity or due execution of this Agreement or
any other Loan Document, nor to make any inquiry respecting the performance by
the Borrower of its obligations hereunder or under any other Loan Document.
Any such inquiry which may be made by the Agent, any Managing Agent or any
Co-Agent shall not obligate it to make any further inquiry or to take any
action.  Each of the Agent, the Managing Agents and the Co-Agents shall be
entitled to rely upon advice of counsel concerning legal matters and upon any
notice, consent, certificate, statement or writing which the Agent, such
Managing Agent or such Co-Agent believes to be genuine and to have been
presented by a proper Person.

       SECTION 9.4   Successor.  Any of the Agent, the Managing Agents and the
Co-Agents may resign as such at any time upon at least 30 days' prior notice to
the Borrower and all Lenders.  If the Agent at any time shall resign, the
Required Lenders may appoint another Lender as the successor Agent which shall
thereupon become the Agent hereunder.  If no successor Agent shall have been so
appointed by the Required Lenders, and shall have accepted such appointment,
within 30 days after the retiring Agent's giving notice of resignation, then
the retiring Agent may, on behalf of the Lenders, appoint a successor Agent,
which shall be one of the Lenders or a commercial banking institution organized
under the laws of the U.S. (or any State thereof) or a U.S. branch or agency of
a commercial banking institution, and having a combined capital and surplus of
at least $500,000,000.  Upon the acceptance of any appointment as the Agent
hereunder by a successor Agent, such successor Agent shall be entitled to
receive from the retiring Agent such documents of transfer and assignment as
such successor Agent may reasonably request, and shall thereupon succeed to and
become vested with all rights, powers, privileges and duties of the retiring
Agent, and the retiring Agent shall be discharged from its duties and
obligations under this Agreement.  After a retiring Agent's, Managing Agent's
or Co-Agent's resignation hereunder as Agent, Managing Agent or Co-Agent, the
provisions of this Article IX shall inure to its benefit as to any actions
taken or omitted to be taken by it while it was the Agent under this Agreement,
and Section 10.4 (and, with respect to the Agent, Section 10.3) shall continue
to inure to its benefit.

       SECTION 9.5   Loans by the Agents.  Each of the Agent, the Managing
Agents and the Co-Agents shall have the same rights and powers with respect to
(x) the Loans made by it or any of its Affiliates, and (y) the Notes held by it
or any of its Affiliates as any other Lender and may exercise the same as if it
were not the Agent, a Managing Agent or a Co- Agent, as the case may be.  Each
of the Agent, the Managing Agents and the Co-Agents and its Affiliates may
accept deposits from, lend money to, and generally engage in any kind of
business with the Borrower or any Subsidiary or Affiliate of the Borrower as if
it were not the Agent, a Managing Agent or a Co-Agent hereunder, as the case
may be.





                                       5
<PAGE>   8
       SECTION 9.6   Credit Decisions.  Each Lender acknowledges that it has
made its own credit decision to extend its Commitments hereunder (i)
independently of each of the Agent, the Managing Agents, the Co-Agents and each
other Lender, and (ii) based on such Lender's review of the financial
information of the Borrower, this Agreement, the other Loan Documents (the
terms and provisions of which being satisfactory to such Lender) and such other
documents, information and investigations as such Lender has deemed
appropriate.  Each Lender also acknowledges that it will continue to make its
own credit decisions as to exercising or not exercising from time to time any
rights and privileges available to it under this Agreement or any other Loan
Document (i) independently of each of the Agent, the Managing Agents, the Co-
Agents and each other Lender, and (ii) based on such other documents,
information and investigations as it shall deem appropriate at any time.

       SECTION 9.7   Copies, etc.  The Agent shall give prompt notice to each
Lender of each notice or request required or permitted to be given to the Agent
by the Borrower pursuant to the terms of this Agreement (unless concurrently
delivered to the Lenders by the Borrower).  The Agent will distribute to each
Lender each document or instrument received for its account and copies of all
other communications received by the Agent from the Borrower for distribution
to the Lenders by the Agent in accordance with the terms of this Agreement."

       G.     Section 10.4 of the Credit Agreement is hereby amended in its
entirety to read as follows:

       "SECTION 10.4 Indemnification.  In consideration of the execution and
delivery of this Agreement by each Lender and the extension of the Commitments,
the Borrower hereby indemnifies, exonerates and holds the Agent, each Managing
Agent, each Co-Agent and each Lender and each of their respective officers,
directors, employees and agents (collectively, the "Indemnified Parties"),
whether or not related to any negligence of the Indemnified Parties, free and
harmless from and against any and all actions, causes of action, suits, losses,
costs, liabilities and damages, and expenses incurred in connection therewith
(irrespective of whether any such Indemnified Party is a party to the action
for which indemnification hereunder is sought), including reasonable attorneys'
fees and disbursements (collectively, the "Indemnified Liabilities"), incurred
by the Indemnified Parties or any of them as a result of, or arising out of, or
relating to  any transaction financed or to be financed in whole or in part,
directly or indirectly, with the proceeds of any Loan;  the entering into and
performance of this Agreement and any other Loan Document by any of the
Indemnified Parties; any investigation, litigation or proceeding related to any
acquisition or proposed acquisition by the Borrower or any of its Significant
Subsidiaries of all or any portion of the stock or assets of any Person,
whether or not the Agent, such Managing Agent, such Co-Agent or such Lender is
party thereto;  any investigation, litigation or proceeding related to any
environmental cleanup, audit, compliance or other matter relating to the
protection of the environment or the Release by the Borrower or any of its
Significant Subsidiaries of any Hazardous Material; or  the presence on or
under, or the escape, seepage, leakage, spillage, discharge, emission,
discharging or releases from, any





                                       6
<PAGE>   9
real property owned or operated by the Borrower or any Subsidiary thereof of
any Hazardous Material (including any losses, liabilities, damages, injuries,
costs, expenses or claims asserted or arising under any Environmental Law),
regardless of whether caused by, or within the control of, the Borrower or such
Subsidiary, except for any such Indemnified Liabilities arising for the account
of a particular Indemnified Party by reason of the relevant Indemnified Party's
gross negligence or wilful misconduct.  If and to the extent that the foregoing
undertaking may be unenforceable for any reason, the Borrower hereby agrees to
make the maximum contribution to the payment and satisfaction of each of the
Indemnified Liabilities which is permissible under applicable law."

       H.     Clause (d) of Section 10.1 of the Credit Agreement is hereby
amended and restated in it entirety to read as follows:

       "(d)   affect adversely the interests, rights or obligations of the
Agent as Agent, any Managing Agent as Managing Agent or any Co-Agent as
Co-Agent shall be made without the consent of such Agent, Managing Agent or
Co-Agent."

       I.     Section 10.3 of the Credit Agreement is amended by inserting
"(i)" in the second line after the word "of", by deleting "(i)" from the fourth
line after the word "with", and by adding the phrase "the Agent and the Lenders
in connection with" after the "(ii)" in the eight line.

       J.     (i) The definition of "Guarantor" in Section 1.1 of the Credit
Agreement is hereby amended by deleting the section reference "Section 7.1.10"
and inserting the section reference "Section 7.1.9" in its place; (ii) Section
2.5.1 of the Credit Agreement is hereby amended by deleting the word "day" from
the second line and inserting the term "Business Day" in its place; (iii)
Section 10.1(b) of the Credit Agreement is hereby amended by deleting the
section reference "Section 2.2.2" and inserting the section reference "Section
2.3" in its place; and (iv) Section 10.11.2 of the Credit Agreement is hereby
amended by adding the reference "4.7," after "4.6," and before "4.8" in the
second line of the last sentence.

       K.     The second sentence of Section 2.2.4(a) of the Credit Agreement
is hereby amended and restated in its entirety to read as follows:

       "Each Competitive Bid Quote must comply with the requirements of this
Section 2.2.4 and must be submitted to the Agent by telecopy (except in the
case of UBS) at its offices specified in Section 10.2 not later than (i) in the
case of a Eurodollar Auction, (A) with respect to UBS, 12:45 p.m. (New York
time), at least three Business Days prior to the proposed Borrowing Date and
(B) with respect to each other Lender, 1:00 p.m. (New York time), at least
three Business Days prior to the proposed Borrowing Date, or (ii) in the case
of an Absolute Rate Auction, (A) with respect to UBS, 9:45 a.m. (New York time)
on the proposed Borrowing Date and (B) with respect to each other Lender, 10:00
a.m. (New York time) on the proposed





                                       7
<PAGE>   10
Borrowing Date (or, with respect to clauses (i) and (ii) and upon reasonable
prior notice to the Lenders, such other time and date as the Borrower and the
Agent may agree provided that UBS shall submit its Competive Bid Quote fifteen
minutes before the time that the other Lenders are required to submit their
Competitive Bid Quotes)."

       SECTION 3.    Conditions to Effectiveness.

       A.     Sections 2(D) and 2(E) and, except as provided in the following
Section 3(B), all other provisions of this First Amendment shall become
effective on October 15, 1996, provided that the Agent shall have received all
of the following, in form and substance satisfactory to the Agent, and in
sufficient number of signed counterparts to provide one for each Lender:

              (i)    Counterparts of this First Amendment, duly executed by
       each of the Borrower, the Lenders, the Agent, the Managing Agents and
       the Co-Agents; and

              (ii)   A certificate of the Secretary or an Assistant Secretary
       of the Borrower (x) certifying that the resolutions of its Board of
       Directors authorizing the execution, delivery and performance of the
       Credit Agreement remain in full force and effect, and (y) identifying
       its Authorized Officers authorized to sign this First Amendment and
       attaching a sample of the true signature of each such officer.

       B.     Sections 2(A), 2(B), 2(C), 2(F) and 2(G) of this First Amendment
shall become effective on October 18, 1996, conditioned upon the satisfaction
of the conditions described in Sections 3(A)(i) and (ii) and upon the
fulfillment of the following additional conditions:

              (i)    Duly executed promissory notes substantially in the form
       of Exhibits 2.2.1, 2.8A and 2.8B to the Credit Agreement payable to the
       order of each Lender;

              (ii)   Payment by each Lender (other than UBS) to the Agent of
       the amount shown in Exhibit A to this First Amendment; and

              (iii)  Such other documents as the Agent may reasonably request.

       C.     Upon the effectiveness of the entire First Amendment and
satisfaction of all the conditions in this Section 3, (i) each Lender signatory
to this First Amendment shall for all purposes be a Lender party to the Credit
Agreement as amended by this First Amendment and any other Loan Documents
executed by the Lenders and shall have the rights and obligations of a Lender
under the Loan Documents to the same extent as if they were originally parties
to the Credit Agreement, and no further consent or action by the Borrower, any
Lender, the Agent, any Managing Agent or any Co- Agent shall be required and
the Lenders (including UBS) shall have the Commitment and percentages set forth
in Exhibit B hereto, and (ii) to the extent that its Commitment, Percentage,
rights and obligations under the Credit Agreement have been





                                       8
<PAGE>   11
amended in connection with this First Amendment, UBS in its capacity as a
Lender shall be released from its obligations under the Credit Agreement and
under the other Loan Documents and the Commitment and Percentage of UBS in its
capacity as a Lender shall be modified as provided in this First Amendment.
Each Lender, each Managing Agent and each Co-Agent hereby acknowledges and
consents to the amendments in Sections 2(D) and 2(E).

       SECTION 4.    Representations and Warranties.  To induce the Lenders,
the Agent, the Managing Agents and the Co- Agents to enter into this First
Amendment, the Borrower hereby reaffirms, as of the date hereof, its
representations and warranties contained in Article VI of the Credit Agreement
and in each other Loan Document to which it is a party (except to the extent
such representations and warranties relate solely to an earlier date) and
additionally represents and warrants as follows:

       A.     Authorization; No Conflict.  The execution and delivery of this
First Amendment and the performance by the Borrower of its Obligations under
this First Amendment, the Credit Agreement as amended by this First Amendment,
and the other Loan Documents, are within the Borrower's corporate powers, have
been duly authorized by all necessary corporate action and do not contravene or
conflict with any provision of law or of the articles of incorporation, bylaws
or other organic documents of the Borrower, or of any material agreement
binding upon the Borrower.

       B.     Validity and Binding Nature.  This First Amendment and the Credit
Agreement as amended by this First Amendment are legal, valid and binding
obligations of the Borrower, enforceable against the Borrower in accordance
with their respective terms except as (i) enforceability thereof may be limited
by bankruptcy, insolvency or similar laws affecting creditors' rights generally
and (ii) rights of acceleration and the availability of equitable remedies may
be limited by equitable principles of general applicability.

       C.     Consents.  No action, consent or approval of, or registration or
filing with, or any other action by any governmental authority is required in
connection with the execution, delivery and performance by the Borrower of this
First Amendment, the Credit Agreement as amended by this First Amendment, or
any other Loan Document or the legality, validity, binding effect or
enforceability of this First Amendment, the Credit Agreement as amended by this
First Amendment, or the other Loan Documents.

       SECTION 5.    Reaffirmation of Credit Agreement.  This First Amendment
shall be deemed to be an amendment to the Credit Agreement, and the Credit
Agreement, as amended hereby, is hereby ratified, approved and confirmed in
each and every respect.  All references to the Credit Agreement in any other
document, instrument, agreement or writing shall hereafter be deemed to refer
to the Credit Agreement as amended hereby.





                                       9
<PAGE>   12
       SECTION 6.    Headings.  The various headings of this First Amendment
are inserted for convenience only and shall not affect the meaning or
interpretation of this First Amendment or any provisions hereof or thereof.

       SECTION 7.    Governing Law; Entire Agreement.  THIS FIRST AMENDMENT
SHALL BE DEEMED TO BE A CONTRACT MADE UNDER AND GOVERNED BY THE INTERNAL LAWS
OF THE STATE OF NEW YORK.  This First Amendment constitutes the entire
understanding among the parties hereto with respect to the subject matter
hereof and supersede any prior agreements, written or oral, with respect
thereto.

       SECTION 8.    Execution in Counterparts, Effectiveness, etc.  This First
Amendment may be executed by the parties hereto in several counterparts, each
of which shall be executed by the different parties on different counterparts
and be deemed to be an original and all of which shall constitute together but
one and the same First Amendment.

       SECTION 9.    Successors and Assigns.  This First Amendment shall be
binding upon and shall inure to the benefit of the parties hereto and their
respective successors and assigns; provided, however, that:  the Borrower may
not assign or transfer its rights or obligations hereunder without the prior
written consent of the Agent and all Lenders; and the rights of sale,
assignment and transfer of the Lenders are subject to Section 10.11 of the
Credit Agreement.

       SECTION 10.   Waiver of Jury Trial.  THE AGENT, THE MANAGING AGENTS, THE
CO-AGENTS, THE LENDERS AND THE BORROWER HEREBY KNOWINGLY, VOLUNTARILY AND
INTENTIONALLY WAIVE ANY RIGHTS THEY MAY HAVE TO A TRIAL BY JURY IN RESPECT OF
ANY LITIGATION BASED HEREON, OR ARISING OUT OF, UNDER, OR IN CONNECTION WITH,
THIS FIRST AMENDMENT, UNDER THE CREDIT AGREEMENT, UNDER ANY OTHER LOAN
DOCUMENT, UNDER ANY AMENDMENT, INSTRUMENT, DOCUMENT OR AGREEMENT DELIVERED OR
WHICH MAY BE DELIVERED IN CONNECTION HEREWITH OR THEREWITH OR UNDER ANY COURSE
OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR
ACTIONS OF THE AGENT, THE MANAGING AGENTS, THE CO-AGENTS, THE LENDERS OR THE
BORROWER.  THE BORROWER ACKNOWLEDGES AND AGREES THAT IT HAS RECEIVED FULL AND
SUFFICIENT CONSIDERATION FOR THIS PROVISION (AND EACH OTHER PROVISION OF EACH
OTHER LOAN DOCUMENT TO WHICH IT IS A PARTY) AND THAT THIS PROVISION IS A
MATERIAL INDUCEMENT FOR THE AGENT, THE MANAGING AGENTS, THE CO-AGENTS AND THE
LENDERS ENTERING INTO THIS FIRST AMENDMENT AND EACH SUCH OTHER LOAN DOCUMENT.

       SECTION 11.   Forum Selection and Consent to Jurisdiction.  ANY
LITIGATION BASED HEREON, OR ARISING OUT OF, UNDER, OR IN CONNECTION WITH, THIS





                                       10
<PAGE>   13
FIRST AMENDMENT, UNDER THE CREDIT AGREEMENT, UNDER ANY OTHER LOAN DOCUMENT,
UNDER ANY AMENDMENT, INSTRUMENT, DOCUMENT OR AGREEMENT DELIVERED OR WHICH MAY
BE DELIVERED IN CONNECTION HEREWITH OR THEREWITH OR UNDER ANY COURSE OF
CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS
OF THE AGENT, THE MANAGING AGENTS, THE CO-AGENTS, THE LENDERS OR THE BORROWER
SHALL BE BROUGHT AND MAINTAINED EXCLUSIVELY IN THE COURTS OF THE STATE OF NEW
YORK OR IN THE UNITED STATES DISTRICT COURT FOR THE SOUTHERN DISTRICT OF NEW
YORK; PROVIDED, HOWEVER, THAT ANY SUIT SEEKING ENFORCEMENT AGAINST ANY
COLLATERAL OR OTHER PROPERTY MAY BE BROUGHT, AT THE AGENT'S OPTION, IN THE
COURTS OF ANY JURISDICTION WHERE SUCH COLLATERAL OR OTHER PROPERTY MAY BE
FOUND.  THE BORROWER, THE AGENT, EACH MANAGING AGENT, EACH CO-AGENT AND EACH
LENDER HEREBY EXPRESSLY AND IRREVOCABLY SUBMIT TO THE JURISDICTION OF THE
COURTS OF THE STATE OF NEW YORK AND OF THE UNITED STATES DISTRICT COURT FOR THE
SOUTHERN DISTRICT OF NEW YORK FOR THE PURPOSE OF ANY SUCH LITIGATION AS SET
FORTH ABOVE AND IRREVOCABLY AGREE TO BE BOUND BY ANY JUDGMENT RENDERED THEREBY
IN CONNECTION WITH SUCH LITIGATION.  THE BORROWER, THE AGENT, EACH MANAGING
AGENT, EACH CO-AGENT AND EACH LENDER FURTHER IRREVOCABLY CONSENT TO THE SERVICE
OF PROCESS BY REGISTERED MAIL, POSTAGE PREPAID, OR BY PERSONAL SERVICE WITHIN
OR WITHOUT THE STATE OF NEW YORK.  THE BORROWER, THE AGENT, EACH MANAGING
AGENT, EACH CO-AGENT AND EACH LENDER HEREBY EXPRESSLY AND IRREVOCABLY WAIVE, TO
THE FULLEST EXTENT PERMITTED BY LAW, ANY OBJECTION WHICH IT MAY HAVE OR
HEREAFTER MAY HAVE TO THE LAYING OF VENUE OF ANY SUCH LITIGATION BROUGHT IN ANY
SUCH COURT REFERRED TO ABOVE AND ANY CLAIM THAT ANY SUCH LITIGATION HAS BEEN
BROUGHT IN AN INCONVENIENT FORUM.  TO THE EXTENT THAT THE BORROWER HAS OR
HEREAFTER MAY ACQUIRE ANY IMMUNITY FROM JURISDICTION OF ANY COURT OR FROM ANY
LEGAL PROCESS (WHETHER THROUGH SERVICE OF NOTICE, ATTACHMENT PRIOR TO JUDGMENT,
ATTACHMENT IN AID OF EXECUTION OR OTHERWISE) WITH RESPECT TO ITSELF OR ITS
PROPERTY, THE BORROWER HEREBY IRREVOCABLY WAIVES SUCH IMMUNITY IN RESPECT OF
ITS OBLIGATIONS UNDER THIS AGREEMENT AND THE OTHER LOAN DOCUMENTS.

       SECTION 12.   Severability.  Any provision of this First Amendment, the
Credit Agreement as amended by this First Amendment or any other Loan Document
which is prohibited or unenforceable in any jurisdiction shall, as to such
provision and such jurisdiction, be ineffective to the extent of such
prohibition or unenforceability without invalidating the





                                       11
<PAGE>   14
remaining provisions of this First Amendment, the Credit Agreement as amended
by this First Amendment or such Loan Document or affecting the validity or
enforceability of such provision in any other jurisdiction.

       SECTION 13.   No Oral Agreements.  THIS WRITTEN FIRST AMENDMENT TOGETHER
WITH THE OTHER LOAN DOCUMENTS REPRESENTS THE FINAL AGREEMENT BETWEEN THE
PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR
SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.

       THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.





                                       12
<PAGE>   15
       IN WITNESS WHEREOF, the parties hereto have caused this First Amendment
to be executed by their respective officers thereunto duly authorized as of the
day and year first above written and shall be effective as of such date.


                          NOBLE AFFILIATES, INC.
                          
                          
                          By:/s/ WILLIAM D. DICKSON   
                             -----------------------------------------
                          Name:  William D. Dickson
                          Title: Vice President Finance and Treasurer
                          
                          Address:         110 West Broadway
                                  Ardmore, Oklahoma  73401
                          
                          Facsimile No.:           405/221-1386
                          
                          Telephone No.:   405/223-4110
                          
                          Attention:       William D. Dickson

<PAGE>   16
                          UNION BANK OF SWITZERLAND, Houston Agency, 
                          Individually as a Lender and as the Agent
                          
                          
                          By: /s/ EVANS SWANN
                              ------------------------------------------------
                          Name: Evans Swann
                          Title: Managing Director
                          
                          
                          By: /s/ J. FINLEY BIGGERSTAFF
                              ------------------------------------------------
                          Name: J. Finley Biggerstaff
                          Title: Assistant Treasurer
                          
                          Domestic
                          Office:          1100 Louisiana, Suite 4500 
                                           Houston, Texas  77002      
                                                                      
                          Facsimile No.:   (713) 655-6555             
                                                                      
                          Attention:                                  
                          Telephone:       (713) 655-6500             
                                                                      
                          Eurodollar                                  
                          Office:          1100 Louisiana, Suite 4500 
                                           Houston, Texas  77002      
                                                                      
                          Facsimile No.:   (713) 655-6555             
                                                                      
                          Attention:                                  
                          Telephone:       (713) 655-6500             
                                                                      
<PAGE>   17

                          NATIONSBANK OF TEXAS, N.A, 
                          Individually as a Lender and as Managing Agent
                          
                          
                          By: /s/ DALE T. WILSON
                             --------------------------------------------------
                          Name: DALE T. WILSON
                          Title: VICE PRESIDENT
                          
                          Domestic
                          Office:          901 Main Street, 14th Floor 
                                           Dallas, Texas   75202       
                                                                       
                          Facsimile No.:   (214) 508-1215              
                                                                       
                          Attention:       Betty Canales               
                          Telephone:       (214) 508-1225              
                                                                       
                          Eurodollar                                   
                          Office:          901 Main Street, 14th Floor 
                                           Dallas, Texas   75202       
                                                                       
                          Facsimile No.:   (214) 508-1215              
                                                                       
                          Attention:       Betty Canales               
                          Telephone:       (214) 508-1225              
                                                                       
                          Send copies to:                              
                                           NATIONSBANK OF TEXAS, N.A.
                                           303 West Wall Street        
                                           Midland, Texas  79701-4761  
                                                                       
                          Facsimile No.:   (915) 685-2009              
                                                                       
                          Attention:       Dale Wilson                 
                          Telephone:       (915) 685-2193              
                                                                       
<PAGE>   18

                          TEXAS COMMERCE BANK NATIONAL ASSOCIATION, 
                          Individually as a Lender and as Managing Agent
                          
                          
                          By:/s/ DALE S. HURD
                             --------------------------------------------------
                          Name: DALE S. HURD
                          Title: SENIOR VICE PRESIDENT
                          
                          Domestic
                          Office:          2200 Ross Ave., 3rd Floor
                                           Dallas, Texas   75201
                          
                          Facsimile No.:   (214) 965-2389
                          
                          Attention:       Dale Hurd
                          Telephone:       (214) 965-2583
                          
                          
                          Eurodollar
                          Office:          2200 Ross Ave., 3rd Floor
                                           Dallas, Texas   75201
                          
                          Facsimile No.:   (214) 965-2389
                          
                          Attention:       Dale Hurd
                          Telephone:       (214) 965-2583
<PAGE>   19
                          BANK OF MONTREAL, Individually as a Lender 
                          and as Co-Agent
                          
                          
                          By:/s/ ROBERT L. ROBERTS
                             --------------------------------------------------
                          Name: ROBERT L. ROBERTS
                          Title: Director, U.S. Corporate Banking
                          
                          Domestic
                          Office:          115 S. LaSalle, 11W
                                           Chicago, Illinois 60603
                          
                          Facsimile No.:   (312) 750-4326
                          
                          Attention:       Charla Chase
                          Telephone:       (312) 750-4326
                          
                          Eurodollar
                          Office:          115 S. LaSalle,11W
                                           Chicago, Illinois 60603
                          
                          Facsimile No.:   (312) 750-6061
                          
                          Attention:       Charla Chase
                          Telephone:       (312) 750-4326
                          
                          Send copies to:
                          
                                           700 Louisiana, Suite 4400
                                           Houston, Texas 77002
                          
                          Facsimile No.:   (713) 223-4007
                                           
                          Attention:       Robert L. Roberts
                          Telephone:       (713) 546-9754
<PAGE>   20
                          CIBC INC., Individually as a Lender and as Co-Agent
                          
                          
                          By:/s/ GARY C. GASKILL
                             --------------------------------------------------
                          Name: Gary C. Gaskill
                          Title: AUTHORIZED SIGNATORY
                          
                          Domestic
                          Office:         2727 Paces Ferry Rd.
                                          Suite 1200
                                          Atlanta, Georgia   30339
                          
                          Facsimile No.:  (270) 319-4950
                          
                          Attention:      Joan Moseley
                          Telephone:      (270) 319-4828
                          
                          Eurodollar
                          Office:         2727 Paces Ferry Rd.
                                          Suite 1200
                                          Atlanta, Georgia   30339
                          
                          Facsimile No.:  (270) 319-4950
                          
                          Attention:      Joan Moseley
                          Telephone:      (270) 319-4828
                          
                          Send copies to:
                          
                                          909 Fannin, Suite 1200
                                          Houston, TX 77010
                          
                          Facsimile No.:  (713) 658-9922
                          
                          Attention:      Brian Myers
                          Telephone:      (713) 658-5230
<PAGE>   21
                          THE FIRST NATIONAL BANK OF CHICAGO, 
                          Individually as a Lender and as Co-Agent
                          
                          
                          By: /s/ GAIL F. SCANNELL
                             --------------------------------------------------
                          Name: Gail F. Scannell
                          Title: Assistant Vice President
                          
                          Domestic
                          Office:          One First National Plaza 
                                           0634, 1FNP, 10           
                                           Chicago, IL   60670      
                          
                          Facsimile No.:   (312) 732-4840
                          
                          Attention:       John Beirne
                          Telephone:       (312) 732-3659
                          
                          Eurodollar
                          Office:          One First National Plaza
                                           0634, 1FNP, 10          
                                           Chicago, IL   60670     
                          
                          Facsimile No.:   (312) 732-4840
                          
                          Attention:       John Beirne
                          Telephone:       (312) 732-3659
                          
                          Send copies to:
                          
                                           1100 Louisiana, Suite 3200
                                           Houston, TX 77002
                          
                          Facsimile No.:   (713) 654-7370
                          
                          Attention:       Ron Dierker   
                          Telephone:       (713) 654-7341
<PAGE>   22
                          ROYAL BANK OF CANADA, Individually as a Lender 
                          and as Co-Agent
                          
                          
                          By: /s/ LINDA M. STEPHENS
                             --------------------------------------------------
                          Name: LINDA M. STEPHENS
                          Title: MANAGER
                          
                          Domestic
                          Office:            1 Financial Square
                                             New York, New York 10005-3531
                          
                          
                          Facsimile No.:     (212) 428 2372
                          
                          Attention:         Linda Smith, Loan Administrator
                          Telephone:         (212) 428 6323
                          
                          Eurodollar
                          Office:            1 Financial Square
                                             New York, New York 10005-3531
                          
                          
                          Facsimile No.:     (212) 428 2372
                          
                          Attention:         Linda Smith, Loan Administrator
                          Telephone:         (212) 428 6323
<PAGE>   23
                          SOCIETE GENERALE, SOUTHWEST AGENCY, 
                          Individually as a Lender and as Co-Agent
                          
                          
                          By: /s/ MATTHEW C. FLANIGAN
                             --------------------------------------------------
                          Name: MATTHEW C. FLANIGAN
                          Title: FIRST VICE PRESIDENT AND MANAGER
                          
                          Domestic
                          Office:          2001 Ross Ave., Suite 4800
                                           Dallas, Texas   75201     
                          
                          Facsimile No.:   (214) 979-1104
                          
                          Attention:       Richard Lewis 
                          Telephone:       (214) 979-2759
                          
                          Eurodollar
                          Office:          2001 Ross Ave., Suite 4800
                                           Dallas, Texas   75201     
                          
                          Facsimile No.:   (214) 754-0171
                          
                          Attention:       Ralph Saheb  
                          Telephone:       (214) 979-2764
<PAGE>   24
                          BANK OF AMERICA ILLINOIS,
                          as a Lender
                          
                          
                          By: /s/ MICHAEL J. DILLON
                             --------------------------------------------------
                          Name: Michael J. Dillon
                          Title: Managing Director
                          
                          Domestic
                          Office: Bank of America NT&SA
                                  1850 Gateway Blvd., 4th Fl.
                                  Concord, CA 94520
                          
                          Facsimile No.: (510) 603-7254
                          
                          Attention: George Korolkov
                          Telephone: (510) 675-7335
                          
                          With a copy to: Bank of America
                          
                          Address: 333 Clay Street, Suite 4550
                                   Houston, TX 77002
                          
                          Facsimile No.: (713) 651-4808
                          
                          Attention: Michael J. Dillon
                          Telephone: (713) 651-4903
                          
                          Eurodollar
                          Office: Bank of America NT&SA
                                  1850 Gateway Blvd., 4th Fl.
                                  Concord, CA 94520
                          
                          Facsimile No.: (510) 603-7254
                          
                          Attention: George Korolkov
                          Telephone: (510) 675-7335
                          
                          With a copy to: Bank of America
                          
                          Address: 333 Clay Street, Suite 4550
                                   Houston, TX 77002
                          
                          Facsimile No.: (713) 651-4808
                          
                          Attention: Michael J. Dillon
                          Telephone: (713) 651-4903
<PAGE>   25
                          THE BANK OF NEW YORK, as a Lender
                          
                          
                          By: /s/ RAYMOND J. PALMER
                             --------------------------------------------------
                          Name: Raymond J. Palmer
                          Title: Vice President
                          
                          Domestic
                          Office:          The Energy Industries Division      
                                           One Wall Street, 19th Floor         
                                           New York, New York   10286          
                                                                               
                          Facsimile No.:   (212) 635-7923
                                                                               
                          Attention:       Raymond Palmer                      
                          Telephone:       (212) 635-7834                      
                                                                               
                          Eurodollar                                           
                          Office:          Eurodollar/Cayman Funding Area      
                                           101 Barclay Street                  
                                           New York, New York   10286          
                          
                          Facsimile No.:   (212) 635-7923
                          
                          Attention:  Carol Tafurd
                          Telephone:  (212) 635-7550
<PAGE>   26
                          BANQUE PARIBAS, as a Lender
                          
                          
                          By: /s/ BARTON D. SCHOUEST
                             ------------------------------------------- 
                          Name: Barton D. Schouest
                          Title: Group Vice President
                          
                          
                          By: /s/ MICHAEL FIUZAT
                             ------------------------------------------- 
                          Name: Michael Fiuzat
                          Title: Assistant Vice President
                          
                          Domestic
                          Office: 1200 Smith Street, Suite 3100
                                  Houston, Texas   77002
                          
                          Facsimile No.:  (713) 659-5305
                          
                          Attention:
                          Telephone:
                          
                          Eurodollar
                          Office: 1200 Smith Street, Suite 3100
                                  Houston, Texas   77002
                          
                          Facsimile No.:  (713) 659-6915
                          
                          Attention:
                          Telephone:
<PAGE>   27
                          THE FUJI BANK, LIMITED - HOUSTON AGENCY, as a Lender
                          
                          
                          By:          /s/ YOSHIAKI INOUE
                             --------------------------------------------------
                          Name:            Yoshiaki Inoue
                          Title:           Vice President
                          
                          Domestic
                          Office:          One Houston Center     
                                           Suite 4100             
                                           1221 McKinney Street   
                                           Houston, Texas   77010 
                          
                          Facsimile No.:   (713) 759-0048
                          
                          Attention:       Jenny Lin     
                          Telephone:       (713) 650-7821
                          
                          Eurodollar
                          Office:          One Houston Center     
                                           Suite 4100             
                                           1221 McKinney Street   
                                           Houston, Texas   77010 
                          
                          Facsimile No.:   (713) 759-0048
                          
                          Attention:       Jenny Lin     
                          Telephone:       (713) 650-7821
<PAGE>   28
                          FIRST UNION NATIONAL BANK OF NORTH CAROLINA, 
                          as a Lender
                          
                          
                          By:         /s/ MICHAEL J. KOLOSOWSKY
                             --------------------------------------------------
                          Name:           Michael J. Kolosowsky
                          Title:          Vice President
                          
                          Domestic
                          Office:         301 South College Street
                                          Charlotte, N.C.   28288
                          
                          Facsimile No.:  (713) 650-6354
                          
                          Attention:
                          Telephone:
                          
                          Eurodollar
                          Office:         301 South College Street
                                          Charlotte, N.C.  28288
                          
                          Facsimile No.:  (713) 650-6354
                          
                          Attention:
                          Telephone:
                          
                          Send copies to:
                          
                                          1001 Fannin Street, Suite 2255
                                          Houston, TX 77002
                          
                          Facsimile No.:  (713) 650-6354
                          
                          Attention:      Russell Clingman
                          Telephone:      (713) 650-3619
<PAGE>   29
                          CREDIT LYONNAIS, NEW YORK BRANCH,
                          as a Lender
                          
                          
                          By:         /s/ PASCAL POUPELLE
                             --------------------------------------------------
                          Name:           Pascal Poupelle
                          Title:          Senior Vice President
                          
                          Domestic
                          Office:         Credit Lyonnais New York Branch
                                          c/o Credit Lyonnais Houston
                                          Representative Office
                                          1000 Louisiana, Suite 5360
                                          Houston, TX 77002

                          
                          Facsimile No.:  (713) 751-0307
                          
                          Attention:      Ms. Bernadette Archie
                          Telephone:      (713) 751-0500
                          
                          Eurodollar
                          Office:         Credit Lyonnais New York Branch
                                          c/o Credit Lyonnais Houston
                                          Representative Office
                                          1000 Louisiana, Suite 5360
                                          Houston, TX 77002
                          
                          
                          Facsimile No.:  (713) 751-0307
                          
                          Attention:      Ms. Bernadette Archie
                          Telephone:      (713) 751-0500
<PAGE>   30
                          MELLON BANK, N.A., as a Lender
                          
                          
                          By:         /s/ E. MARC CUENOD, JR.
                             --------------------------------------------------
                          Name:           E. Marc Cuenod, Jr.
                          Title:          First Vice President
                          
                          Domestic
                          Office:         Three Mellon Bank Center
                                          #2307                   
                                          Pittsburgh, PA   15258  
                          
                          Facsimile No.:  (412) 236-2027
                          
                          Attention:      Jennifer Ratay
                          Telephone:      (412) 234-5767
                          
                          Eurodollar
                          Office:         Three Mellon Bank Center
                                          #2307
                                          Pittsburgh, PA   15258
                          
                          Facsimile No.:  (412) 236-2027
                          
                          Attention:      Jennifer Ratay
                          Telephone:      (412) 234-5767
                          
                          Send copies to:
                          
                                          1100 Louisiana, Suite 3600
                                          Houston, Texas 77002
                          
                          Facsimile No.:  (713) 650-3409
                          
                          Attention:      Melissa Bauman
                          Telephone:      (713) 759-3070
<PAGE>   31
                          THE SANWA BANK LTD., DALLAS AGENCY, as a Lender
                          
                          
                          By:             /s/ BLAKE WRIGHT                 
                             --------------------------------------------------
                          Name:           Blake Wright
                          Title:          Vice President
                          
                          Domestic
                          Office:         2200 Ross Avenue
                                          Dallas, Texas   75201
                          
                          Facsimile No.:  (214) 741-6535
                          
                          Attention:
                          Telephone:
                          
                          Eurodollar
                          Office:         2200 Ross Avenue
                                          Dallas, Texas   75201
                          
                          Facsimile No.:  (214) 741-6535
                          
                          Attention:
                          Telephone:
<PAGE>   32
                          THE SUMITOMO BANK, LIMITED,
                          HOUSTON AGENCY, as a Lender
                          
                          
                          By:         /s/ TOSHIRO KUBOTA        
                             ----------------------------------                 
                          Name:       Toshiro Kubota
                          Title:      Joint General Manager
                          
                          Domestic
                          Office:     700 Louisiana St, Suite 1750
                                      Houston, Texas   77002      
                          
                          Facsimile No.:  (713) 238-8291
                          
                          Attention:  Robert Quezada
                          Telephone:  (713) 238-8221
                          
                          Eurodollar
                          Office:     700 Louisiana St, Suite 1750
                                      Houston, Texas   77002      
                          
                          Facsimile No.:  (713) 238-8291
                          
                          Attention:  Robert Quezada
                          Telephone:  (713) 238-8221
<PAGE>   33
                          LIBERTY BANK AND TRUST COMPANY
                          OF OKLAHOMA CITY, N.A., as a Lender
                          
                          
                          By:  /s/ LAURA CHRISTOFFERSON            
                             --------------------------------------------------
                             Name:   Laura Christofferson
                             Title:  Vice President
                          
                          Domestic
                          Office:         100 North Broadway       
                                          Oklahoma City, OK   73102
                          
                          Facsimile No.:  (405) 231-6788
                          
                          Attention:      Laura Christofferson
                          Telephone:      (405) 231-6853      
                          
                          Eurodollar
                          Office:         100 North Broadway       
                                          Oklahoma City, OK   73102
                          
                          Facsimile No.:  (405) 231-6788
                          
                          Attention:      Laura Christofferson 
                          Telephone:      (405) 231-6853       
<PAGE>   34
                      CONSENT AND AGREEMENT OF GUARANTORS

         The undersigned Guarantor hereby consents and acknowledges that this
First Amendment shall be deemed to be an amendment to the Credit Agreement, and
the Credit Agreement, as amended hereby, is hereby ratified, approved and
confirmed in each and every respect.  The Guarantor acknowledges that the
Guaranty remains in full force and effect and guarantees the Obligations of the
Borrower pursuant to the Credit Agreement as amended by this First Amendment.
All references to the Credit Agreement in the Guaranty and any other document,
instrument, agreement or writing to which the Guarantor is party shall
hereafter be deemed to refer to the Credit Agreement as amended by this First
Amendment.


                         SAMEDAN OIL COMPANY,
                         as Guarantor
                         
                         
                         By   /s/ W D DICKSON                                
                            --------------------------------------            
                         Name:  W D Dickson
                         Title: VP-Finance
                         
                         
                         ENERGY DEVELOPMENT COMPANY,
                         as Guarantor
                         
                         
                         By   /s/ W D DICKSON                                  
                            -------------------------------------              
                         Name:   W D Dickson
                         Title:  VP-Finance
<PAGE>   35
                                  EXHIBIT "A"



<TABLE>
<CAPTION>
NAME OF LENDER                                     AMOUNT PAYABLE TO AGENT
- --------------                                     -----------------------
                                                        
                                                        
<S>                                                   <C>
NationsBank of Texas, N.A.                            62,500,000.00
                                                  
Texas Commerce Bank National Association              62,500,000.00
                                                  
Bank of America Illinois                              50,000,000.00
                                                  
Bank of Montreal                                      50,000,000.00
                                                  
The Bank of New York                                  50,000,000.00
                                                  
Banque Paribas                                        50,000,000.00
                                                  
CIBC Inc.                                             50,000,000.00
                                                  
The First National Bank of Chicago                    50,000,000.00
                                                  
The Fuji Bank, Limited -                              50,000,000.00
  Houston Agency                                  
                                                  
Royal Bank of Canada                                  50,000,000.00
                                                  
Societe Generale, Southwest Agency                    50,000,000.00
                                                  
First Union National Bank                             35,000,000.00
  of North Carolina                               
                                                  
Credit Lyonnais New York Branch                       25,000,000.00
                                                  
Mellon Bank, N.A.                                     25,000,000.00
                                                  
The Sanwa Bank Ltd., Dallas Agency                    25,000,000.00
                                                  
The Sumitomo Bank, Limited,                           25,000,000.00
  Houston Agency                                  
                                                  
Liberty Bank and Trust Company                        15,000,000.00
  of Oklahoma City, N.A.                          
</TABLE>
<PAGE>   36
                                  EXHIBIT "B"

<TABLE>
<CAPTION>
                                                 COMMITMENT        COMMITMENT
NAME OF LENDER                                   $ MILLIONS        PERCENTAGE
- --------------                                   ----------        ----------
<S>                                                <C>               <C>    
Union Bank of Switzerland, Houston Agency            $75             9.3750%
                                                                            
NationsBank of Texas, N.A.                            62.5           7.8125%
                                                                            
Texas Commerce Bank National Association              62.5           7.8125%
                                                                            
Bank of America Illinois                              50             6.2500%
                                                                            
Bank of Montreal                                      50             6.2500%
                                                                            
The Bank of New York                                  50             6.2500%
                                                                            
Banque Paribas                                        50             6.2500%
                                                                            
CIBC Inc.                                             50             6.2500%
                                                                            
The First National Bank of Chicago                    50             6.2500%
                                                                            
The Fuji Bank, Limited -                                                    
  Houston Agency                                      50             6.2500%
                                                                            
Royal Bank of Canada                                  50             6.2500%
                                                                            
Societe Generale, Southwest Agency                    50             6.2500%
                                                                            
First Union Bank of North Carolina                    35             4.3750%
                                                                            
Credit Lyonnais New York Branch                       25             3.1250%
                                                                            
Mellon Bank, N.A.                                     25             3.1250%
                                                                            
The Sanwa Bank Ltd., Dallas Agency                    25             3.1250%
                                                                            
The Sumitomo Bank, Limited,                           25             3.1250%
  Houston Agency                                                            
                                                                            
Liberty Bank and Trust Company                        15             1.8750%
  of Oklahoma City, N.A.                                                   
                                                 ----------        --------
                                                              
  TOTAL                                            $800            100.0000%
</TABLE>                                                      
                                                              
                                                              
                                                              

<PAGE>   1
                                                                     EXHIBIT 5.1


                    [LETTERHEAD OF THOMPSON & KNIGHT, P.C.]



                                October 16, 1996



Noble Affiliates, Inc.
110 West Broadway
Ardmore, Oklahoma 73401

Dear Sirs:

         We have acted as counsel for Noble Affiliates, Inc., a Delaware
corporation (the "Company"), in connection with the preparation of the
Company's Registration Statement on Form S-3 (the "Registration Statement")
filed with the Securities and Exchange Commission (the "Commission") relating
to the registration of a maximum of 6,275,579 shares (the "Shares") of Common
Stock, par value $3.33 1/3 per share ("Common Stock"), of the Company under the
Securities Act of 1933, as amended (the "Securities Act").  The prospectus
forming a part of the Registration Statement covers the proposed sale from time
to time by UBS Securities LLC (the "Purchaser") of such of the Shares as may be
acquired by the Purchaser upon conversion of the 4 1/4% Convertible
Subordinated Notes due November 1, 2003 (the "Notes") of the Company into
Common Stock (the "Conversion Shares") or pursuant to and subject to the terms
and conditions of a Standby Agreement between the Company and the Purchaser
(the "Standby Agreement"), the form of which is filed as Exhibit 1.1 to the
Registration Statement (the "Purchased Shares").

         In connection with the foregoing, we have examined the originals or
copies, certified or otherwise authenticated to our satisfaction, of the
Registration Statement, the form of the Standby Agreement and such corporate
records of the Company, certificates of public officials and of officers of the
Company, and other agreements, instruments and documents as we have deemed
necessary to require as a basis for the opinions hereinafter expressed.  Where
facts material to the opinions hereinafter expressed were not independently
established by us, we have relied upon the statements of officers of the
Company, where we deemed such reliance appropriate under the circumstances.

         Based upon the foregoing and in reliance thereon, and subject to the
assumptions and qualifications hereinafter specified, it is our opinion that:

         1.      The Company has been duly incorporated and is validly existing
and in good standing under the laws of the State of Delaware.

         2.      The Conversion Shares have been duly authorized for issuance
by the Company and, when issued and delivered upon conversion of the Notes as
described in the prospectus forming a part of the Registration Statement, will
be legally issued, fully paid and nonassessable.

         3.      The Purchased Shares to be sold by the Company pursuant to the
Standby Agreement have been duly authorized for issuance by the Company and,
when issued and delivered against payment therefor as described in the
prospectus forming a part of the Registration Statement, will be legally
issued, fully paid and nonassessable.

         We are members of the Bar of the State of Texas only and do not
purport to be experts on the laws of any state or jurisdiction other than the
State of Texas and the United States.  Insofar as the opinions expressed herein
relate to matters governed by Delaware law, we have relied solely upon a
reading of the applicable statutes and the corporate records of the Company and
certificates of public officials and officers of the Company referenced above
with respect to the opinions given herein.
<PAGE>   2
Noble Affiliates, Inc.
October 16, 1996
Page 2


         We hereby consent to the filing of this opinion with the Commission as
an exhibit to the Registration Statement and to the reference to us under the
caption "Validity of Common Stock" in the prospectus forming a part of the
Registration Statement.  In giving this consent, we do not thereby admit that
we come within the category of persons whose consent is required under Section
7 of the Securities Act or the rules or regulations of the Commission
thereunder.



                                             Respectfully submitted,
                                             
                                             THOMPSON & KNIGHT,
                                             A Professional Corporation
                                             
                                             
                                             By: /s/ MICHAEL L. BENGTSON       
                                                -------------------------------
                                                 Michael L. Bengtson, Attorney
                                             

<PAGE>   1
                                                                   EXHIBIT 23.1

                  CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS



As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our report dated January 26, 1996,
included on page 33 of the 1995 Annual Report to Shareholders and incorporated
by reference in the Noble Affiliates, Inc. Form 10-K for the year ended
December 31, 1995, as amended by Form 10-K/A (No.1), dated June 27, 1996, and
to all references to our Firm included in this registration statement.


                                                ARTHUR ANDERSEN LLP

Oklahoma City, Oklahoma
  October 15, 1996

<PAGE>   1
                                                                    EXHIBIT 23.2

                         INDEPENDENT AUDITORS' CONSENT



Noble Affiliates, Inc.
Ardmore, Oklahoma


We consent to the incorporation by reference in the Registration Statements of
Noble Affiliates, Inc. on Form S-3 of our report on Energy Development
Corporation dated February 16, 1996 (July 2, 1996 as to Notes 1 and 10)
appearing in Form 8-K (Date of Event:  July 31, 1996) of Noble Affiliates,
Inc., as amended, and to the reference to us under the heading "Experts" in the
Prospectus, which is part of this Registration Statement.


/s/ Deloitte & Touche LLP

Houston, Texas
October 15, 1996

<PAGE>   1
                                                                    EXHIBIT 23.4



                 CONSENT OF INDEPENDENT PETROLEUM ENGINEERS

We hereby consent to the use of our report to Energy Development Corporation
dated September 27, 1996, and titled "Proved Reserves as of July 1, 1996,"
contained in the Company's Form 8-K (Date of Event:  July 31, 1996), as
amended, in the Prospectus constituting part of the Noble Affiliates, Inc.
Securities and Exchange Commission Form S-3 and to the references to Miller and
Lents, Ltd. under the headings "The Company - Properties - Reserves" and
"Experts."


                                               MILLER AND LENTS, LTD.



                                               By:  /s/ James C. Pearson
                                                  ----------------------------
                                                    James C. Pearson,
                                                    President



Houston, Texas
October 16, 1996


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission