SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549
                                ________________
                                 SCHEDULE 14D-1

                   Tender Offer Statement Pursuant to Section
                14(d)(1) of the Securities Exchange Act of 1934
                               (Amendment No. 2)
                                ________________
                               COMSAT CORPORATION
                           (Name of Subject Company)

                                  REGULUS, LLC
                          LOCKHEED MARTIN CORPORATION
                                   (Bidders)

                        COMMON STOCK, WITHOUT PAR VALUE
                         (Title of Class of Securities)

                                   20564D107
                     (CUSIP Number of Class of Securities)

                             STEPHEN M. PIPER, ESQ.
                          LOCKHEED MARTIN CORPORATION
                              6801 ROCKLEDGE DRIVE
                            BETHESDA, MARYLAND 20817
                                 (301) 897-6000

                 (Name, Address and Telephone Number of Person
     Authorized to Receive Notices and Communications on behalf of Bidders)

                                    COPY TO:
                              DAVID G. LITT, ESQ.
                             O'MELVENY & MYERS LLP
                             555 13TH STREET, N.W.
                                 SUITE 500 WEST
                          WASHINGTON, D.C.  20004-1109
                                 (202) 383-5300


                           CALCULATION OF FILING FEE

Transaction Valuation(1):  $1,169,509,386       Amount of Filing Fee:  $227,901

 
(1)  Estimated for purposes of calculating the amount of the filing fee only.
     The amount assumes the purchase of 25,703,503 shares of common stock,
     without par value (the "Shares"), of COMSAT Corporation (the "Company") at
     a price per Share of $45.50 in cash (the "Offer Price").  Such number of
     shares represents 49% of the shares of Common Stock of the Company
     outstanding as of September 11, 1998, minus the number of shares of the
     Series II Common Stock of the Company outstanding as of September 11, 1998.

[x]  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:    $227,901         Filing Parties:  Regulus, LLC and
                                             Lockheed Martin Corporation
Form or registration no.:  Schedule 14D-1   Date Filed: September 25, 1998

                        (Continued on following page(s))


                               Page 2 of 7 Pages

 
     This Amendment No. 2 to the Tender Offer Statement on Schedule 14D-1 (the
"Schedule 14D-1") amends and supplements the Schedule 14D-1 of Regulus, LLC, a
single member Delaware limited liability company (the "Purchaser") and a wholly-
owned subsidiary of Lockheed Martin Corporation, a Maryland corporation
("Parent"), in respect of the tender offer (the "Offer") by the Purchaser to
purchase up to 49% (less certain adjustments) of the issued and outstanding
shares (the "Shares") of common stock, without par value, of COMSAT Corporation,
a District of Columbia corporation (the "Company"), at a price of $45.50 per
Share, net to the seller in cash, without interest thereon, upon the terms and
subject to the conditions set forth in the Offer to Purchase dated September 25,
1998 (the "Offer to Purchase") and in the related Letter of Transmittal.  The
Offer is being made pursuant to an Agreement and Plan of Merger dated as of
September 18, 1998, among the Company, Parent and Deneb Corporation, a wholly-
owned subsidiary of Parent.  The Schedule 14D-1 was initially filed with the
Securities and Exchange Commission on September 25, 1998.  Capitalized terms not
defined herein have the meanings assigned thereto in the Schedule 14D-1 and the
Offer to Purchase, which is attached as Exhibit (a)(1) to the Schedule 14D-1.

     The Purchaser and Parent hereby amend and supplement the Schedule 14D-1 as
follows:

The Cover Page to the Schedule 14D-1 setting forth certain information regarding
the Purchaser erroneously listed the Purchaser's I.R.S. Identification No. as
52-2121081 in response to Item 1.  The correct I.R.S. Identification No. for the
Purchaser is 52-1893632, the same as the I.R.S. Identification No. for Parent,
and the Cover Page to the Schedule 14D-1 is hereby amended to reflect the
foregoing change.

ITEM 10.  ADDITIONAL INFORMATION.

     Item 10(b) is hereby amended and supplemented by the addition of the
following paragraph thereto:

          On October 16, 1998, Parent, the Purchaser and the Company filed
applications with the FCC for consent to transfer control of CGSI, which holds
two fixed earth station licenses with respect to earth stations located in
Clarksburg, Maryland for the provision of international fixed satellite service
and an FCC authorization pursuant to Section 214 of the Communications Act to
provide international common carrier services on a resale basis.  On the same
date, the Purchaser filed an application with the FCC for consent to become an
Authorized Carrier and acquire up to 49% of the Company's Common Stock as an
Authorized Carrier.

     Item 10(f) is hereby amended and supplemented by the addition of the
following paragraph thereto:

          On October 22, 1998, the Board of Directors of Parent declared a two-
for-one split of the Parent Common Stock and a cash dividend increase.  The
stock split will be in the form of a stock dividend and stockholders of record
on December 1, 1998, will receive one additional share of Parent Common Stock
for each share of Parent Common Stock held.  The new shares will be issued on
December 31.

                               Page 3 of 7 Pages

 
          The split will have the effect of altering the Merger Consideration
contemplated by the Merger Agreement such that each Share issued and outstanding
immediately prior to the Effective Time (other than shares of Company Common
Stock held in the treasury of the Company, held by the Purchaser, held by
Parent, if any, and Dissenting Shares, if any) will be converted into the right
to receive 1.0 share of Parent Common Stock.

          December 1 also will be the record date for the fourth-quarter cash
dividend of $.44, or $1.76 annually, on pre-split shares of Parent Common Stock,
($.22 quarterly on a post-split basis) representing a $.04 per share increase
over the previous cash dividend of $.40 per share.  The dividend will be payable
on December 31.

          On October 22, 1998, Parent issued the press release attached hereto
as Exhibit (a)(9) with relation to the foregoing.  The full text of the press
release is incorporated herein by reference.

          On November 17, 1998, Parent issued a press release pursuant to which
it announced that the Purchaser had extended the Offer until 12:00 midnight, New
York City time on Thursday, January 14, 1999.  The terms of the extended Offer
otherwise remain the same as those of the original Offer as set forth in the
Offer to Purchase filed with the Securities and Exchange Commission on September
25, 1998.  The Offer is being extended because certain required regulatory and
shareholder approvals have not yet been obtained.

          According to First Chicago Trust Company of New York, the depositary
for the offer, as of the close of business on November 16, 1998, 5,422,628
shares of Company Common Stock had been validly tendered and not withdrawn
pursuant to the Offer.  None of these shares were tendered pursuant to notices
of guaranteed delivery.

          On November 17, 1998, Parent issued the press release attached hereto
as Exhibit (a)(10) with relation to the extension of the Offer.  The full text
of the press release is incorporated herein by reference.

ITEM 11.    MATERIAL TO BE FILED AS EXHIBITS.

     Item 11 is hereby amended and supplemented by the addition of the following
paragraph thereto:

          (a)(9) Text of Press Release issued October 22, 1998

          (a)(10)  Text of Press Release issued November 17, 1998

                               Page 4 of 7 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.



                                    November 18, 1998



                                    REGULUS, LLC


 
                                    By: /s/ Stephen M. Piper
                                       ---------------------
                                    Name:  Stephen M. Piper
                                    Title: Vice President

                               Page 5 of 7 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.



                                    November 18, 1998



                                    LOCKHEED MARTIN CORPORATION


 

                                    By: /s/  Stephen M. Piper
                                       ----------------------------------
                                    Name:  Stephen M. Piper
                                    Title: Associate General Counsel and
                                            Assistant Secretary

                               Page 6 of 7 Pages

 
                               14D-EXHIBIT INDEX

EXHIBIT   DESCRIPTION
- -------   -----------


(a)(9)    Text of Press Release issued October 22, 1998

(a)(10)   Text of Press Release issued November 17, 1998


                               Page 7 of 7 Pages

 
                                                              EXHIBIT (a)9

For Immediate Release

LOCKHEED MARTIN BOARD AUTHORIZES TWO-FOR-ONE STOCK SPLIT, DIVIDEND INCREASE

BETHESDA, Maryland, October 22, 1998  The board of directors of Lockheed Martin
(NYSE:LMT) today declared a two-for-one split of the Corporation's common stock
and a cash dividend increase.

The split will be in the form of a stock dividend and stockholders of record on
December 1, 1998, will receive one additional share for each share of Lockheed
Martin Corporation common stock held.  The new shares will be issued 
December 31, 1998.

The split will have the effect of altering the exchange ratio contemplated by
the Agreement and Plan of Merger between Lockheed Martin and COMSAT Corporation
from 0.5 to 1.0, as previously announced, to a one-for-one exchange ratio.

December 1 also will be the record date for the fourth-quarter cash dividend of
$.44, or $1.76 annually, on pre-split shares, ($.22 quarterly on a post-split
basis) representing a $.04 per-share increase over the previous cash dividend of
$.40 per share.  The dividend will be payable on December 31.

CONTACT:  Charles Manor, Lockheed Martin News & Information, 301/897-6258.
 


 
                                                                   Exhibit (a)10
                                                                   -------------

LOCKHEED MARTIN EXTENDS
COMSAT TENDER OFFER
UNTIL JANUARY 14, 1999


BETHESDA, Maryland, November 17, 1998 --Lockheed Martin Corporation (NYSE:LMT)
announced today that its wholly-owned subsidiary, Regulus, LLC, is extending its
offer to purchase up to 49% (less certain adjustments) of the outstanding shares
of common stock of COMSAT Corporation (NYSE:CQ) at a price of $45.50 per share,
net to the seller in cash, until 12:00 midnight, New York City time, on
Thursday, January 14, 1999.

The offer previously had been scheduled to expire on November 24, 1998.  The
terms of the extended offer otherwise remain the same as those of the original
offer as set forth in the offering materials filed with the Securities &
Exchange Commission on September 25, 1998.  The offer is being extended because
certain required regulatory and shareholder approvals have not yet been
obtained.

As noted in the offering materials, it is expected that a significant period of
time will elapse between the commencement and the consummation of the offer,
while the parties seek to obtain the regulatory approvals required in order to
satisfy the conditions to the offer.  The expiration date may be required to be
extended one or more additional times while such regulatory approvals are
sought.  In addition, in view of the need for U.S. congressional legislation
relating to the amendment or repeal of the Satellite Act, and for additional
regulatory approvals as conditions to the consummation of the merger, there may
be a further significant period of time between the purchase of shares pursuant
to the offer and the consummation of the merger.  There can be no assurance that
any such regulatory approvals will be obtained or that any such legislation will
be enacted, and if obtained and enacted, there can be no assurance as to the
date such approval and enactments will occur.

According to First Chicago Trust Company of New York, the depositary for the
offer, as of the close of business on November 16, 1998, 5,422,678 shares of
COMSAT Corporation common stock had been validly tendered and not withdrawn
pursuant to the offer.  None of these shares were tendered pursuant to notices
of guaranteed delivery.

The Information Agent for the offer is Morrow & Co., Inc. and questions about
the tender offer may be addressed to it at 1-800/566-9061.  The Dealer Manager
is Bear, Stearns & Co. Inc. and questions may be addressed to it at 1-877/762-
5237.

The proposed $2.7-billion Lockheed Martin/COMSAT strategic combination was
announced September 20, 1998.  Upon completion of the transaction, COMSAT will
become an integral element
 


 
of Lockheed Martin Global Telecommunications, a wholly owned subsidiary formed
to provide global telecommunications services to corporate and government
customers worldwide.

                                     # # #

CONTACT:  Charles Manor, Lockheed Martin News & Information, 301/897-6258



NOTE:  Statements which are not historical facts are forward-looking
       statements made pursuant to the safe harbor provision of the Private
       Securities Litigation Reform Act of 1995.  Such forward-looking
       statements involve risks and uncertainties that could cause actual
       results to differ materially from anticipated results including the
       effects of government budgets and requirements, economic conditions,
       competitive environment, timing of awards and contracts; the outcome of
       contingencies including litigation and environmental remediation, and
       program performance in addition to other factors not listed.  See in this
       regard the Corporation's filings with the Securities and Exchange
       Commission.  The Corporation does not undertake any obligation to
       publicly release any revisions to forward-looking statements to reflect
       events or circumstances or changes in expectations after the date of this
       press release or the occurrence of anticipated events.