SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                               ----------------
 
                                 SCHEDULE 14D-1
                                
                             (AMENDMENT NO. 9)     
 
                   TENDER OFFER STATEMENT PURSUANT TO SECTION
                14(D)(1) OF THE SECURITIES EXCHANGE ACT OF 1934
 
                              GRUMMAN CORPORATION
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                           (NAME OF SUBJECT COMPANY)
 
                           NORTHROP ACQUISITION, INC.
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                                    (BIDDER)
 
                    Common Stock, $1.00 par value per share
                       (Including the Associated Rights)
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                         (TITLE OF CLASS OF SECURITIES)
 
                                    40018110
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                     (CUSIP NUMBER OF CLASS OF SECURITIES)
 
                            Richard R. Molleur, Esq.
                              Northrop Corporation
                             1840 Century Park East
                             Los Angeles, CA 90067
                                 (310) 553-6262
 
                                    COPY TO:
 
                             Karen E. Bertero, Esq.
                            Gibson, Dunn & Crutcher
                             333 South Grand Avenue
                             Los Angeles, CA 90071
                                 (213) 229-7000
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                 (NAME, ADDRESS AND TELEPHONE NUMBER OF PERSON
     AUTHORIZED TO RECEIVE NOTICES AND COMMUNICATIONS ON BEHALF OF BIDDER)
 
                           CALCULATION OF FILING FEE
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TRANSACTION VALUATION* AMOUNT OF FILING FEE** $2,174,165,160.00 $434,833.03
- -------------------------------------------------------------------------------- * For purposes of calculating fee only. Assumes purchase of 35,067,180 shares of Common Stock, $1.00 par value per share, of Grumman Corporation at $62.00 per share. ** 1/50th of 1% of Transaction valuation. [_]CHECK 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: Not Applicable Filing party: Not Applicable Form or registration no.: Not Applicable Date filed: Not Applicable Page 1 of 4 Pages This Amendment No. 9 amends and supplements the Tender Offer Statement on Schedule 14D-1 dated March 14, 1994 (the "Schedule 14D-1"), of Northrop Acquisition, Inc. (the "Purchaser") and Northrop Corporation ("Northrop"), as amended, filed in connection with the Purchaser's offer to purchase all of the outstanding shares of Common Stock, par value $1.00 per share, of Grumman Corporation, a New York corporation (the "Company"), and the associated preferred stock purchase rights, as set forth in the Schedule 14D-1, as amended (the "Offer"). ITEM 11. MATERIAL TO BE FILED AS EXHIBITS. (c)(16) Summary newspaper advertisement, dated April 6, 1994.
Page 2 of 4 Pages 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. Dated: April 6, 1994 NORTHROP CORPORATION /s/ Richard R. Molleur ---------------------------------------- Name: Richard R. Molleur Title: Corporate Vice President NORTHROP ACQUISITION, INC. /s/ Richard R. Molleur ---------------------------------------- Name: Richard R. Molleur Title: Vice President and Secretary Page 3 of 4 Pages EXHIBIT INDEX
EXHIBIT NO. DESCRIPTION ------- ----------- (c)(16) Summary newspaper advertisement, dated April 6, 1994.
Page 4 of 4 Pages

 
   
This  announcement is neither  an offer  to purchase nor  a solicitation of  an
 offer to sell Shares. The Offer is made solely by the Offer to Purchase dated
 March  14, 1994, the Supplement thereto  dated April 5, 1994 and  the related
  Letters of  Transmittal, and is  being made to  all holders of  Shares. The
   Purchaser is  not aware of  any state  where the  making of  the Offer  is
   prohibited  by administrative or  judicial action  pursuant to any  valid
    state  statute. If  the  Purchaser  becomes aware  of  any  valid state
    statute  prohibiting  the making  of  the Offer  or the  acceptance  of
     Shares pursuant thereto, the Purchaser  will make a good faith effort
      to comply with any such state  statute or seek to have such  statute
      declared  inapplicable  to the  Offer. If,  after  such good  faith
       effort, the Purchaser cannot  comply with any such state statute,
        the Offer will not be made to (nor will tenders be accepted from
        or on  behalf of) the holders  of Shares in such  state. In any
         jurisdiction where  the  securities, blue  sky or  other  laws
         require the  Offer to be made by a licensed broker or dealer,
          the  Offer will  be  deemed to  be  made on  behalf  of the
           Purchaser  by  Salomon  Brothers   Inc  or  one  or   more
           registered brokers or  dealers licensed under the laws of
           such jurisdiction.     
                           
                        NORTHROP ACQUISITION, INC.     
                            
                         A WHOLLY OWNED SUBSIDIARY     
                                       
                                    OF     
                              
                           NORTHROP CORPORATION     
                    
                 HAS AMENDED ITS TENDER OFFER TO INCREASE     
                               
                            THE CASH PRICE FOR     
                     
                  ALL OUTSTANDING SHARES OF COMMON STOCK     
                        
                     (Including the Associated Rights)     
                                       
                                    OF     
                               
                            GRUMMAN CORPORATION     
                                       
                                    TO     
                              
                           $62.00 NET PER SHARE     
   
  On April 4, 1994, Northrop Acquisition, Inc. (the "Purchaser"), a wholly
owned subsidiary of Northrop Corporation, a Delaware corporation ("Northrop"),
amended its offer to purchase all outstanding shares of Common Stock, par value
$1.00 per share (including the associated Rights, as defined in the Offer to
Purchase) (collectively, the "Shares"), of Grumman Corporation, a New York
corporation (the "Company") to increase the consideration offered to $62.00 per
share, net to the seller in cash, without interest, upon the terms and subject
to the conditions set forth in the Offer to Purchase dated March 14, 1994 (the
"Offer to Purchase"), the Supplement to the Offer to Purchase dated April 5,
1994 (the "Supplement") and in the related Letters of Transmittal (which
collectively constitute the "Offer"). SHARES PREVIOUSLY VALIDLY TENDERED TO THE
PURCHASER AND NOT WITHDRAWN CONSTITUTE VALID TENDERS FOR PURPOSES OF THE OFFER.
THEREFORE, HOLDERS OF SHARES WHO HAVE PREVIOUSLY VALIDLY TENDERED SHARES TO THE
PURCHASER AND HAVE NOT WITHDRAWN SUCH TENDERS AND WHO WISH TO HAVE SUCH SHARES
PURCHASED PURSUANT TO THE OFFER ARE NOT REQUIRED TO TAKE ANY FURTHER ACTION,
EXCEPT AS MAY BE REQUIRED BY THE GUARANTEED DELIVERY PROCEDURE IF SUCH
PROCEDURE WAS UTILIZED.     
       
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    THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT,     
      
   NEW YORK CITY TIME, ON FRIDAY, APRIL 15, 1994, UNLESS EXTENDED.     
  ------------------------------------------------------------------
   
  THE BOARD OF DIRECTORS OF THE COMPANY UNANIMOUSLY HAS DETERMINED THAT THE
OFFER AND THE MERGER ARE FAIR TO, AND IN THE BEST INTERESTS OF, THE COMPANY AND
ITS STOCKHOLDERS, HAS APPROVED THE OFFER AND THE MERGER AND RECOMMENDS THAT
STOCKHOLDERS ACCEPT THE OFFER AND TENDER THEIR SHARES PURSUANT TO THE OFFER.
       
  THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION DATE THAT NUMBER OF SHARES
REPRESENTING AT LEAST TWO-THIRDS OF THE TOTAL NUMBER OF OUTSTANDING SHARES OF
THE COMPANY ON A FULLY DILUTED BASIS. THE OFFER IS ALSO SUBJECT TO CERTAIN
OTHER TERMS AND CONDITIONS AS SET FORTH IN THE OFFER TO PURCHASE.     
   
  THE OFFER IS NOT CONDITIONED UPON THE PURCHASER OBTAINING FINANCING.     
   
  The Offer is being made pursuant to an Agreement and Plan of Merger, dated as
of April 3, 1994 (the "Merger Agreement"), among Northrop, the Purchaser and
the Company. In accordance with the Merger Agreement, the Purchaser has amended
the Offer as herein described. The Merger Agreement also provides that
following the purchase of Shares pursuant to the Offer and the satisfaction of
the other conditions set forth in the Merger Agreement and in accordance with
relevant provisions of the New York Business Corporation Law, the Purchaser
will be merged with and into the Company (the "Merger"). Following consummation
of the Merger, the Company will continue as the surviving corporation and will
be a wholly owned subsidiary of Northrop. At the effective time of the Merger,
each Share issued and outstanding immediately prior thereto (other than Shares
held by the Company as treasury stock or by any subsidiary of the Company or by
Northrop, the Purchaser or any other subsidiary of Northrop and other than
Shares held by a holder who has not voted in favor of the Merger or consented
thereto in writing and who has demanded appraisal for such Shares in accordance
with Section 623 of the New York Business Corporation Law) will be converted
into the right to receive cash without interest in an amount equal to the price
per share paid pursuant to the Offer.     

 
   
  For purposes of the Offer, the Purchaser will be deemed to have accepted for
payment (and thereby purchased) validly tendered Shares when, as and if the
Purchaser gives oral or written notice to the Depositary (as defined in the
Offer to Purchase) of the Purchaser's acceptance of such Shares for payment
pursuant to the Offer. Payment for Shares so accepted for payment will be made
by deposit of the purchase price with the Depositary, which will act as agent
for tendering stockholders for the purpose of receiving payment from the
Purchaser and transmitting payment to validly tendering stockholders. In no
circumstances will interest on the purchase price of Shares be paid by the
Purchaser by reason of any delay in making payment. Payment for Shares
purchased pursuant to the Offer will in all cases be made only after timely
receipt by the Depositary of certificates for such Shares, or timely
confirmation of a book-entry transfer of such Shares into the Depositary's
account at one of the Book-Entry Transfer Facilities described in the Offer to
Purchase pursuant to the procedures set forth in Section 2 of the Offer to
Purchase, a properly completed and duly executed Letter of Transmittal (or
facsimile thereof) or an Agent's Message (as defined in the Offer to Purchase)
and any other documents required by the Letters of Transmittal. The Purchaser
expressly reserves the right, in its sole discretion, at any time or from time
to time, to extend the period of time during which the Offer is open and
thereby delay acceptance for payment of, and the payment for, any Shares, by
giving oral or written notice of such extension to the Depositary. Any such
extension will be followed as promptly as practicable by a public announcement
thereof no later than 9:00 a.m., New York City time, on the next business day
after the previously scheduled Expiration Date. The term "Expiration Date"
means 12:00 Midnight, New York City time, on Friday, April 15, 1994, unless and
until the Purchaser, in its sole discretion, shall have extended the period of
time for which the Offer is open, in which event the term "Expiration Date"
shall mean the latest time and date at which the Offer, as so extended by the
Purchaser, shall expire.     
   
  Tenders of Shares pursuant to the Offer will be irrevocable, except that
Shares tendered pursuant to the Offer may be withdrawn at any time prior to the
Expiration Date and, unless theretofore accepted for payment by the Purchaser
pursuant to the Offer, may also be withdrawn on or after May 13, 1994. For a
withdrawal to be effective, a written, telegraphic, telex or facsimile
transmission notice of withdrawal must be timely received by the Depositary at
one of its addresses set forth on the back cover of the Offer to Purchase. Any
notice of withdrawal must specify the name of the person who tendered the
Shares to be withdrawn, the number of Shares to be withdrawn and the name in
which certificates representing the Shares are registered, if different from
that of the person who tendered the Shares. If certificates for Shares to be
withdrawn have been delivered or otherwise identified to the Depositary, the
serial numbers shown on the particular certificates evidencing such Shares to
be withdrawn must also be furnished to the Depositary prior to the physical
release of the Shares to be withdrawn, together with a signed notice of
withdrawal with signatures guaranteed by an Eligible Institution (as defined in
Section 2 of the Offer to Purchase), except, with respect to signature
guarantees, in the case of Shares tendered by an Eligible Institution. If
Shares have been delivered pursuant to the procedure for book-entry transfer as
set forth in Section 2 of the Offer to Purchase, any notice of withdrawal must
specify the name and number of the account at the appropriate Book-Entry
Transfer Facility to be credited with such withdrawn Shares and must otherwise
comply with such Book-Entry Transfer Facility's procedures. All questions as to
the form and validity (including time of receipt) of notices of withdrawal will
be determined by the Purchaser in its sole discretion, whose determination will
be final and binding.     
   
  THE OFFER TO PURCHASE, THE SUPPLEMENT AND THE RELATED LETTERS OF TRANSMITTAL
CONTAIN IMPORTANT INFORMATION WHICH STOCKHOLDERS SHOULD READ BEFORE MAKING ANY
DECISION WITH RESPECT TO THE OFFER.     
   
  Requests for copies of the Offer to Purchase, the Supplement, the Letters of
Transmittal and other tender offer materials may be directed to the Information
Agent or the Dealer Manager as set forth below, and copies will be furnished
promptly at the Purchaser's expense.     
                     
                  The Information Agent for the Offer is:     
 
                      [LOGO OF GEORGESON & COMPANY INC.]
                                
                             Wall Street Plaza     
                            
                         New York, New York 10005     
                            
                         (213) 509-6240 (collect)     
                      
                   Banks and Brokers call (212) 440-9800     
                          
                       CALL TOLL FREE 1-800-223-2064     
                      
                   The Dealer Manager for the Offer is:     
                              
                           SALOMON BROTHERS INC     
                            
                         Seven World Trade Center     
                            
                         New York, New York 10048     
                                 
                              (212) 783-7769     
                                 
                              (Call Collect)     
   
April 6, 1994