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                     SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549

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                                SCHEDULE TO
                               (Rule 14d-100)
               Tender Offer Statement Under Section 14(d)(1)
         or Section 13(e)(1) of the Securities Exchange Act of 1934
                             (Amendment No. 4)

                       BARRETT RESOURCES CORPORATION
                     (Name of Subject Company (Issuer))

                        RESOURCES ACQUISITION CORP.
                        a wholly owned subsidiary of
                        THE WILLIAMS COMPANIES, INC.
                    (Names of Filing Persons (Offerors))

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                   Common Stock, Par Value $.01 Per Share
         (Including the associated Preferred Stock Purchase Rights)
                       (Title of Class of Securities)

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                                 068480201
                   (CUSIP Number of Class of Securities)

                         William G. von Glahn, Esq.
                 Senior Vice President and General Counsel
                        The Williams Companies, Inc.
                            One Williams Center
                           Tulsa, Oklahoma 74172
                         Telephone: (918) 573-2000

                   (Name, address and telephone number of
                    person authorized to receive notices
              and communications on behalf of filing persons)
                              With a copy to:

                           Morris J. Kramer, Esq.
                         Richard J. Grossman, Esq.
                  Skadden, Arps, Slate, Meagher & Flom LLP
                             Four Times Square
                             New York, NY 10036
                          Telephone: 212-735-3000

                         CALCULATION OF FILING FEE
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    Transaction Valuation*                         Amount of Filing Fee**
      $1,221,326,646                                       $244,265
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*    Estimated for purposes of calculating the amount of the filing fee
     only. The amount assumes the purchase of a total of 16,730,502 shares
     of the outstanding Common Stock, par value $0.01 per share, at a price
     per Share of $73.00 in cash. The amount of the filing fee calculated
     in accordance with Rule 0-11 of the Securities Exchange Act of 1934,
     as amended, equals 1/50 of 1% of the transaction value.
**   The filing fee was paid on May 14, 2001.

[_]      Check the box if any part of the fee is offset as provided by Rule
         0-11(a)(2) and identify the filing with which the offsetting fee
         was previously paid. Identify the previous filing by registration
         statement number or the Form or Schedule and the date of its
         filing.

         Amount Previously Paid:    None              Filing party:   N/A
         Form or Registration No.:  N/A               Date Filed:     N/A

[_]      Check the box if the filing relates solely to preliminary
         communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which
the statement relates:

         [X] third-party tender offer subject to Rule 14d-1.

         [_]      issuer tender offer subject to Rule 13e-4.

         [_]      going-private transaction subject to Rule 13e-3.

         [_]      amendment to Schedule 13D under Rule 13d-2.

         Check the following box if the filing is a final amendment
reporting the results of the tender offer: [_]





         This Amendment No. 4 to the Tender Offer Statement on Schedule TO
(the "Schedule TO"), filed initially with the Securities and Exchange
Commission on May 14, 2001, relates to the offer by Resources Acquisition
Corp. ("Purchaser"), a Delaware corporation and a wholly-owned subsidiary
of The Williams Companies, Inc., a Delaware corporation ("Williams"), to
purchase 16,730,502 shares of the common stock, par value $0.01 per share
(including the associated preferred stock purchase rights, the "Shares") of
Barrett Resources Corporation, a Delaware corporation ("Barrett
Resources"), at $73.00 per Share, net to the seller in cash, upon the terms
and subject to the conditions set forth in the Offer to Purchase and the
accompanying Letter of Transmittal, each dated May 14, 2001, of Purchaser
previously filed as exhibits (a)(1) and (a)(2), respectively, to the
Schedule TO.


Item 7.  Source and Amount of Funds or Other Consideration.

         Item 7 of the Schedule TO, which incorporates by reference certain
information contained in the Offer to Purchase, is hereby amended and
supplemented as follows:

         The subsection entitled "Source and Amount of Funds" of the Offer
to Purchase is hereby amended and supplemented with the following
information:

         On June 11, 2001, Barrett Resources received the consent of its
lenders to the consummation of the Offer and the Merger without repayment
of the amounts owed thereunder as required by The Revolving Credit
Agreement, dated December 15, 2000, among Barrett Resources, as Borrower,
Bank of America, N.A., as Administrative Agent and Issuing Lender, the
Lenders party thereto, Banc of America Securities L.L.C., as Sole Lead
Arranger and Book Manager, Bank One, NA, as Syndication Agent, and Fleet
National Bank, as Documentation Agent.

         The Offer to Purchase previously had disclosed that Williams might
choose to establish a bridge loan facility to fund the capital
contributions to be made to Purchaser by Williams in order for Purchaser to
purchase the Shares sought in the Offer and that Williams was negotiating
the terms of such a bridge loan facility with certain commercial banks and
financial institutions. On June 11, 2001, Williams entered into a Credit
Agreement (the "Credit Agreement") among Williams, as Borrower; Citibank,
N.A. ("Citibank"), Merrill Lynch & Co., and Lehman Commercial Paper Inc.,
as Banks (collectively, the "Banks"); Merrill Lynch & Co., as Syndication
Agent; Lehman Commercial Paper Inc., as Documentation Agent; Salomon Smith
Barney Inc., as Lead Arranger and Book Manager; and Citibank, N.A., as
Administrative Agent (the "Administrative Agent"). The following
description of the Credit Agreement is qualified in its entirety by
reference to the Credit Agreement, a copy of which is filed as exhibit
(b)(1) hereto.

         Pursuant to the Credit Agreement and subject to the terms and
conditions therein, the Banks have committed to advance up to $1.5 billion
to Williams in order (i) to finance the acquisition of up to 100% of the
outstanding Shares of Barrett Resources, other than Shares converted into
shares of Williams common stock pursuant to the terms of the Merger
Agreement (the "Acquisition"), (ii) if necessary or if Williams determines
to do so, to enable Barrett Resources to refinance Barrett Resources' 7.55%
senior notes, accrued interest thereon and any applicable make-whole
amounts under such notes, (iii) if necessary or if Williams determines to
do so, to refinance Barrett Resources' corporate revolving credit facility
and (iv) to finance fees and expenses associated with the Acquisition.
Advances made pursuant to the Credit Agreement will be senior unsecured
obligations of Williams.

         The initial advance pursuant to the Credit Agreement is subject to
certain conditions precedent, including without limitation, (i) receipt by
the Administrative Agent of the Credit Agreement executed by Williams, (ii)
receipt by the Administrative Agent of certain financial statements of
Williams and Barrett Resources, (iii) receipt by the Administrative Agent
of a certificate of an officer of Williams certifying that (a) on the
effective date of the Credit Agreement, there does not exist any judgment,
order, injunction or other restraint with respect to the making of the
advances or which could reasonably be expected to affect the Acquisition,
(b) the Offer, at the time of mailing thereof, did not contain any untrue
statement of a material fact or omit to state any material fact necessary
in order to make the statements therein contained, in light of the circum
stances under which made, not misleading, (c) Williams has received all
governmental and third party approvals necessary in connection with the
acquisition of Shares, and (d) at least 50% of the outstanding Shares have
been tendered to Williams pursuant to the Offer, and (iv) receipt by all
parties to the Credit Agreement of all fees owed by Williams pursuant
thereto.

         The Credit Agreement also contains certain representations,
warranties, covenants, conditions and events of default consistent with
those customarily required for financings of this type and largely
consistent with those contained in Williams' current primary revolving
credit facility. All advances under the Credit Agreement are also subject
to the following conditions: (i) all representations and warranties of
Williams under the Credit Agreement are correct on the date of such
advance, (ii) no Event of Default (as such term is defined in the Credit
Agreement) has occurred and is continuing, and (iii) after giving effect to
such advance the aggregate amount of principal of all advances will not
exceed the aggregate of the commitments.

         All advances made pursuant to the Credit Agreement must be repaid
on or before November 27, 2001. Williams may prepay amounts borrowed, plus
accrued interest, subject to certain notice requirements, without penalty
or premium. Subject to certain exceptions, on the first business day
following receipt by Williams of net cash proceeds from a securities
offering after the effective date of the Credit Agreement, the aggregate
commitments shall be permanently reduced by an amount equal to such net
cash proceeds, and, if the aggregate principal amount of outstanding
advances exceeds the aggregate commitments after such reduction, Williams
shall be required to repay such advances in the amount of such excess.

         Williams may elect to receive either base rate advances or
eurodollar rate advances. Interest on base rate advances shall accrue at a
rate equal to the higher of (a) Citibank's publicly announced base rate, or
(b) .5% above the Federal Funds Rate in effect from time to time. Interest
on eurodollar rate advances shall accrue at a rate equal to the London
interbank offered rate (LIBOR) plus the "Applicable Margin." The Applicable
Margin is determined based on the Standard & Poor's and Moody's ratings of
the senior unsecured long-term debt of Williams. At Williams' current
credit ratings, the Applicable Margin would be 1.125%.


Item 8.  Interest in Securities of the Subject Company

         Item 8 of the Schedule TO, which incorporates by reference certain
information contained in the Offer to Purchase, is hereby amended and
supplemented as follows:

         The Offer expired at 12:00 midnight, eastern time, on Monday, June
11, 2001, and was not extended. Purchaser has accepted for purchase
16,730,502 Shares, comprising approximately 50% of the approximately 33.5
million Shares outstanding prior to the Offer.

         The preliminary count by the Depositary for the Offer indicated
that 21,128,300 Shares were validly tendered and not withdrawn. In
addition, the preliminary count by the Depositary indicated that an
additional 13,672,869 Shares were tendered pursuant to notices of
guaranteed delivery.

         As described in the Offer to Purchase, the determination of the
final proration factor for the Shares purchased is subject to confirmation
and the proper delivery of all Shares tendered pursuant to the guaranteed
delivery procedure. Because of the difficulty of determining precisely the
number of Shares validly tendered and not withdrawn, Purchaser does not
expect to be able to (i) announce the final results of proration, (ii) pay
for Shares accepted for payment, and (iii) return Shares tendered but not
accepted for payment as a result of proration until approximately five New
York Stock Exchange trading days after the Expiration Date.

         On June 12, 2001, Williams issued a press release announcing the
expiration of the Offer and the preliminary results of the Offer, a copy of
which is filed as Exhibit (a)(12) to this Amendment No. 4 and is
incorporated herein by reference.


Item 11. Additional Information.

         Item 11 of the Schedule TO, which incorporates by reference
certain information contained in the Offer to Purchase, is hereby amended
and supplemented as follows:

         On June 12, 2001, Williams issued the press release included as
Exhibit (a)(12) hereto. The information set forth in the press release is
incorporated herein by reference.


Item 12. Exhibits.

         Item 12 of the Schedule TO is hereby amended and supplemented by
including the following information:

         (a)(12)    Press Release issued by Williams on June 12, 2001.
         (b)(1)     Credit Agreement among Williams, as Borrower; Citibank,
                    N.A., Merrill Lynch & Co., and Lehman Commercial Paper
                    Inc., as Banks; Merrill Lynch & Co., as Syndication
                    Agent; Lehman Commercial Paper Inc., as Documen tation
                    Agent; Salomon Smith Barney Inc., as Lead Arranger and
                    Book Manager; and Citibank, N.A., as Administrative
                    Agent.



                                 SIGNATURE

         After due inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete
and correct.

                                              RESOURCES ACQUISITION CORP.


                                              By:  /s/ Ralph A. Hill
                                                  --------------------------
                                              Name:  Ralph A. Hill
                                              Title: Senior Vice President


                                              THE WILLIAMS COMPANIES, INC.


                                              By:  /s/ Keith E. Bailey
                                                  --------------------------
                                              Name:  Keith E. Bailey
                                              Title: Chairman, President and
                                                     Chief Executive Officer


Dated: June 12, 2001


                               EXHIBIT INDEX
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Exhibit
No.          Description

(a)(12)      Press Release issued by Williams on June 12, 2001.
(b)(1)       Credit Agreement among Williams, as Borrower; Citibank, N.A.,
             Merrill Lynch & Co., and Lehman Commercial Paper Inc., as
             Banks; Merrill Lynch & Co., as Syndication Agent; Lehman
             Commercial Paper Inc., as Documentation Agent; Salomon Smith
             Barney Inc., as Lead Arranger and Book Manager; and Citibank,
             N.A., as Administrative Agent.