SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549




                                    FORM 11-K

[ X ]    ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934



         For the fiscal year ended December 31, 1999

         Commission File Number 1-2227

         A.       Full title of the plan:

                  Crown Cork & Seal Company, Inc.
                  Retirement Thrift Plan

         B.       Name of issuer of the Securities held pursuant to the plan and
                  the address of its principal executive office:


                         CROWN CORK & SEAL COMPANY, INC.
                                  ONE CROWN WAY
                           PHILADELPHIA, PA 19154-4599











                                      INDEX


                                                                        Pages


Signatures..........................................................      3

Report of Independent Accountants...................................      6

Audited Plan Financial Statements and Schedules in
accordance with the Financial Reporting Requirements of ERISA........   7 - 14

Exhibit 23 - Consent of Independent Accountants.....................     15








                                   SIGNATURES



Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Committee  has duly caused this annual  report to be signed on its behalf by the
undersigned hereunto duly authorized.






                                      Crown Cork & Seal Company, Inc.
                                      Retirement Thrift Plan




                                   By:/s/ James T. Malec
                                      ------------------
                                      James T. Malec
                                      Member, Benefit Plan Committee

Date: June 28, 2000




        CROWN CORK & SEAL COMPANY, INC.
        RETIREMENT THRIFT PLAN

        Financial Statements as of and for the
        years ended December 31, 1999 and 1998

        Additional information required for Form 5500
        as of and for the year ended December 31, 1999



CROWN CORK & SEAL COMPANY, INC. RETIREMENT
THRIFT PLAN
Table of Contents
- --------------------------------------------------------------------------------






                                                                     Page Number


Report of Independent Accountants                                         1


Basic Financial Statements

      Statement of Net Assets Available for Benefits                      2

      Statement of Changes in Net Assets Available for Benefits           3

      Notes to Financial Statements                                     4 - 8


Additional Information *

      Schedule I -     Schedule of Assets Held for Investment Purposes    9




* Other supplemental schedules required by Section 2520.103-10 of the Department
  of Labor Rules and Regulations  for Reporting and Disclosure  under ERISA have
  been omitted because they are not applicable.



                       Report of Independent Accountants


To the Benefit Plans Committee and Participants of the
Crown Cork & Seal Company, Inc. Retirement Thrift Plan

In our opinion, the accompanying  statement of net assets available for benefits
and the  related  statement  of  changes in net assets  available  for  benefits
present fairly, in all material respects,  the net assets available for benefits
of the Crown Cork & Seal Company,  Inc.  Retirement  Thrift Plan (the "Plan") at
December 31, 1999 and 1998, and the changes in net assets available for benefits
for the years then ended,  in conformity with  accounting  principles  generally
accepted in the United States. These financial statements are the responsibility
of the Plan's  management;  our responsibility is to express an opinion on these
financial  statements  based on our  audits.  We  conducted  our audits of these
statements  in  accordance  with auditing  standards  generally  accepted in the
United  States,  which  require  that we plan and  perform  the  audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the  amounts  and  disclosures  in  the  financial  statements,   assessing  the
accounting  principles  used and significant  estimates made by management,  and
evaluating the overall  financial  statement  presentation.  We believe that our
audits provide a reasonable basis for the opinion expressed above.

Our audits  were  conducted  for the  purpose of forming an opinion on the basic
financial statements taken as a whole. The supplemental  schedule of assets held
for investment  purposes is presented for the purpose of additional analysis and
is not a required part of the basic  financial  statements but is  supplementary
information  required by the  Department  of Labor's Rules and  Regulations  for
Reporting and Disclosure  under the Employee  Retirement  Income Security Act of
1974. This supplemental schedule is the responsibility of the Plan's management.
The supplemental  schedule has been subjected to the auditing procedures applied
in the audits of the basic financial  statements  and, in our opinion, is fairly
stated in all material  respects in relation to the basic  financial  statements
taken as a whole.



PricewaterhouseCoopers LLP

Philadelphia, Pennsylvania
June 22, 2000


                                      -1-




CROWN CORK & SEAL COMPANY, INC. RETIREMENT
THRIFT PLAN
Statement of Net Assets Available for Benefits
- --------------------------------------------------------------------------------


                                                                                   As of December 31,
                                                                             1999                     1998
                                                                     ---------------------------------------------
                                                                                         
Investments, at fair value
Registered investment companies:
  Vanguard 500 Index Fund                                                $ 42,456,089 *           $ 14,971,747
  Vanguard Balanced Index Fund                                              8,562,339 *              2,246,055
  Vanguard Explorer Fund                                                    6,017,959 *              1,544,789
  Vanguard International Growth Fund                                        3,567,039                1,370,130
  Vanguard Total Bond Market Index Fund                                     5,434,830 *                566,288
                                                                     ----------------------------------------------
                                                                           66,038,256               20,699,009
Vanguard Retirement Savings Trust                                          24,974,650 *              7,592,121
Crown Cork & Seal Company, Inc. Stock Fund                                  1,199,100                1,345,762
Participant Loans                                                           1,888,304                        -
                                                                     ----------------------------------------------
        Total investments                                                  94,100,310               29,636,892
                                                                     ----------------------------------------------

Asset transfer from the Crown Cork & Seal
  Company, Inc. 401(k) Retirement Savings Plan
  for Employees of Risdon Corporation                                               -               24,471,702
                                                                     ----------------------------------------------

Receivables
Employer's contributions                                                      202,674                   29,874
Participants' contributions                                                   774,783                  339,595
                                                                     ----------------------------------------------
        Total receivables                                                     977,457                  369,469
                                                                     ----------------------------------------------

Net assets available for benefits                                        $ 95,077,767             $ 54,478,063
                                                                     ==============================================

<FN>
* Represents 5% or more of net assets available for benefits.
</FN>





The accompanying notes are an integral part of these financial statements.

                                      -2-



CROWN CORK & SEAL COMPANY, INC. RETIREMENT
THRIFT PLAN
Statement of Changes in Net Assets Available for Benefits
- --------------------------------------------------------------------------------



                                                                                Year Ended December 31,
                                                                             1999                     1998
                                                                     ---------------------------------------------
                                                                                            
Additions
Investment income:
     Interest and dividend income, investments                           $  3,166,079             $    806,609
     Interest income, participant loans                                        99,511                        -
     Net appreciation in fair value of investments                          7,133,792                2,659,218
                                                                     ---------------------------------------------
                                                                           10,399,382                3,465,827
                                                                     ---------------------------------------------

Contributions:
     Employer                                                               1,848,980                  796,550
     Participant                                                            7,374,432                3,816,787
                                                                     ---------------------------------------------
                                                                            9,223,412                4,613,337
                                                                     ---------------------------------------------

Asset transfers in                                                         29,157,940               24,471,702
                                                                     ---------------------------------------------
        Total additions                                                    48,780,734               32,550,866
                                                                     ---------------------------------------------


Deductions
Payment of benefits                                                         8,160,035                2,209,231
Administrative expenses                                                        20,995                   25,125
                                                                     ---------------------------------------------
        Total deductions                                                    8,181,030                2,234,356
                                                                     ---------------------------------------------

Net increase                                                               40,599,704               30,316,510

Net assets available for plan benefits:
     Beginning of period                                                   54,478,063               24,161,553
                                                                     ---------------------------------------------
     End of period                                                      $  95,077,767            $  54,478,063
                                                                     =============================================



The accompanying notes are an integral part of these financial statements.


                                      -3-



CROWN CORK & SEAL COMPANY, INC. RETIREMENT THRIFT PLAN

Notes to Financial Statements
- --------------------------------------------------------------------------------


NOTE 1 - DESCRIPTION OF PLAN

The  following  description  of the Crown Cork & Seal Company,  Inc.  Retirement
Thrift Plan (the "Plan") provides only general information.  Participants should
refer  to the  Plan  document  for a more  complete  description  of the  Plan's
provisions.

General
The plan is a voluntary defined contribution plan which is designed to provide a
convenient method by which eligible  employees may save regularly through salary
deferrals.  Participation  in the  Plan  is  determined  by an  agreement  among
recognized  collective bargaining units and Crown Cork & Seal Company, Inc. (the
"Company")  or as otherwise  agreed upon  between the Company and  non-organized
hourly  employees.  The Plan is  administered  by the Crown Cork & Seal Company,
Inc.  Benefit Plans  Committee  (the  "Committee").  The Committee has appointed
Vanguard Fiduciary Trust Company ("VFTC") as the trustee of the Plan.

The Plan provides certain employees the opportunity to purchase Company stock at
a purchase price equal to the closing price on the day of deposit.

The participant  accounts of the  non-salaried  participants of the Crown Cork &
Seal  Company,  Inc. 401 (k)  Retirement  Savings  Plan for  Employees of Risdon
Corporation  ("Risdon 401(k)"),  the Crown Cork & Seal Company,  Inc. Retirement
Thrift Plan for Non-Salaried Employees of CONSTAR International,  Inc. ("CONSTAR
Thrift"),  the participant accounts of the non-salaried  employees of the Zeller
Plastik,  Inc.  401(k) Savings Plan  ("Zeller"),  the Crown Cork & Seal Company,
Inc.  Retirement Thrift Plan for  International  Association of Machinists Local
1584 of  Fremont  Plant  No.62  ("Fremont  Thrift")  and the  Crown  Cork & Seal
Company, Inc. Retirement Thrift Plan for International Association of Machinists
Local 1528 of Modesto Plant No. 79 ("Modesto  Thrift") were merged with and into
the Plan effective December 31, 1998, March 31, 1999, August 31, 1999, September
30, 1999, and September 30, 1999,  respectively.  The assets transferred totaled
$24,471,702 for Risdon,  $17,926,398  for CONSTAR  Thrift,  $977,972 for Zeller,
$5,358,924 for Fremont Thrift and $4,633,372 for Modesto  Thrift.  An additional
amount of $261,274 in assets was  transferred to VFTC for Risdon 401(k) in 1999.
During  the  conversion   process  freeze  periods  were  enforced  to  restrict
transactions.  Once the freeze  periods  were lifted  participants  could change
investment elections.

Contributions
Participants  may elect to make  basic  and  supplemental  contributions  (where
permitted)  each  pay  period.  Participants  direct  the  investment  of  their
contributions  into  various  ivestment  options as listed  offered by the Plan.
Basic contributions may be matched by the Company at various rates. Supplemental
contributions  (where  permitted)  are not matched by the Company.  In addition,
certain  participants  receive fixed  contributions  from the Company at varying
rates.  Participants  should  refer to the  Plan  document  for a more  complete
description of the Plan's provisions.

Participant Accounts
Each participant's  account is credited with the participant's  contribution and
allocation of (a) the Company's  contribution and (b) Plan earnings, and charged
with  an  allocation  of  administrative  expenses.  Allocations  are  based  on
participant  earnings or account  balances,  as defined.  The benefit to which a
participant   is  entitled  is  the  benefit  that  can  be  provided  from  the
participant's vested account.


                                      -4-


CROWN CORK & SEAL COMPANY, INC. RETIREMENT THRIFT PLAN

Notes to Financial Statements
- --------------------------------------------------------------------------------

Vesting
Participants are immediately vested in their  contributions plus actual earnings
thereon.  Vesting  in the  Company's  matching  contribution  portion  of  their
accounts plus  earnings  thereon is based on various  rates  established  in the
collective bargaining agreements or in the plan documents. A participant becomes
100 percent vested after completing 4 or 5 years of service, as defined.

Participant Loans
Former  participants  of the Risdon 401(k),  Zeller and Modesto Thrift Plans who
became participants of the Plan through merger activity, and who had outstanding
loans with their former plans,  were allowed to transfer their  outstanding loan
balances to the Plan. Loan terms for  participants of each of these former plans
were as follows:

         Risdon 401(k) - Participants  were able to obtain a loan from this plan
         in an amount of $500 or more, repayable over one to five years, with no
         more than one loan made to a participant  in any calendar  year, and no
         more than two loans  outstanding  at any time.  The  amount of the loan
         plus the outstanding  balance of any other loan to the participant from
         this  plan  could not  exceed  the  lesser of 50% of the  participant's
         account  balance or $50,000.  The interest rate charged for participant
         loans  was fixed  for the term of the loan and was  based  upon  market
         interest rates for similar loans at the time of application.

         Zeller -  Participants  were able to obtain a loan from this plan in an
         amount of $1,000 or more,  repayable  over one to five  years,  with no
         more than two loans made to a participant  in any calendar year, and no
         more than two loans  outstanding  at any time.  The  amount of the loan
         plus any outstanding  balance of any other loan to the participant from
         this  plan  could not  exceed  the  lesser of 50% of the  participant's
         vested  account  balance or  $50,000.  The  interest  rate  charged for
         participant loans was determined by this plan's sponsor.

         Modesto Thrift - Participants were able to borrow from their accounts a
         minimum  of  $1,000,  not to  exceed  50% of the  participant's  vested
         balance up to $50,000.  The repayment of any loan could not exceed five
         years,  unless the loan was granted for the  purpose of  acquiring  the
         primary residence of the participant, in which case it could not exceed
         thirty  years or the  number of full years from the date of the loan to
         the  participant's  normal  retirement date. The interest rate for each
         loan was the prime rate as  published  in the most  recent  Wall Street
         Journal (West Coast Edition).

Payment of Benefits
On  termination of service due to  retirement,  attainment of age 65,  permanent
plant shutdown,  permanent disability,  or death, the participant  automatically
becomes fully vested in the Company contributions. Distributions to participants
are generally paid only in a lump sum. Certain  participants  have the option of
being paid through monthly installments.

Forfeited Accounts
Total unallocated  forfeitures were $12,698 and $68,397 at December 31, 1999 and
1998,  respectively.  These  amounts  will  be used to  reduce  future  employer
contributions.  In 1999,  employer  contributions were reduced by forfeitures of
$210,903.

Plan Termination
The Company  reserves the right to amend or modify any of the  provisions of the
Plan in any respect  retroactively in order to qualify or maintain the Plan as a
plan meeting the requirements of the Employee  Retirement Income Security Act of
1974 ("ERISA") or any other applicable  legislation.  The Plan is subject to the
provisions  of ERISA.  Although  it has not  expressed  any intent to do so, the
Company has the right under the Plan to  discontinue  its  contributions  at any
time and to terminate the Plan subject to the provisions of ERISA.  In the event
of Plan  termination,  participants  will  become  100  percent  vested in their
accounts.

Investment Options
During the plan years ending December 31, 1999 and 1998,  participants were able
to allocate their contributions among the following investment options:

         Vanguard 500 Index Fund:  Seeks to provide  long-term growth of capital
         and income from dividends by holding all of the 500 stocks that make up
         the  unmanaged  Standard & Poor's 500  Composite  Stock Price Index,  a
         widely recognized benchmark of U.S. stock market performance.

         Vanguard  Balanced  Index Fund:  Seeks to provide  income and long-term
         growth of capital and income by  dividing  its assets  between  indexed
         portfolios of stocks (60%) and bonds (40%).

         Vanguard Explorer Fund: Seeks to provide long-term growth of capital by
         investing in a diversified group of small-company stocks with prospects
         for above-average growth.


                                      -5-


CROWN CORK & SEAL COMPANY, INC. RETIREMENT THRIFT PLAN

Notes to Financial Statements
- --------------------------------------------------------------------------------

         Vanguard  International  Growth Fund: Seeks to provide long-term growth
         of capital by investing in stocks of high-quality,  seasoned  companies
         based outside the United States.  Stocks are selected from more than 15
         countries.

         Vanguard Total Bond Market Index Fund: Seeks to provide a high level of
         interest income by attempting to match the performance of the unmanaged
         Lehman  Brothers  Aggregate  Bond Index,  which is a widely  recognized
         measure of the entire taxable U.S. bond market.

         Vanguard  Retirement  Savings Trust: Seeks stability of principal and a
         high  level of  current  income  consistent  with a two- to  three-year
         average maturity.  The trust is a tax-exempt  collective trust invested
         primarily in  investment  contracts  issued by insurance  companies and
         commercial banks, and similar types of fixed-principal investments. The
         trust intends to maintain a constant net asset value of $1.00 per unit.

         Crown  Cork &  Seal  Company, Inc. Stock Fund: Invests in Crown  Cork &
         Seal  stock to  provide the  possibility of  long-term   growth through
         increases  in  the  value  of  the  stock and  the  reinvestment of its
         dividends.

NOTE 2 - SUMMARY OF ACCOUNTING POLICIES

The following  accounting  policies,  which conform with  accounting  principles
generally  accepted in the United  States,  have been used  consistently  in the
preparation of the Plan's financial statements:

Basis of Accounting
The financial  statements of the Plan are prepared  under the accrual  method of
accounting.

Financial Statement Presentation
The  plan  adopted  Statement  of  Position  ("SOP")  99-3,  Accounting  for and
Reporting of Certain  Defined  Contribution  Benefit Plan  Investments and Other
Disclosure Matters. Certain reclassifications of the 1998 amounts have been made
to  conform  to the 1999  presentation  in  accordance  with SOP 99-3.  This SOP
eliminated  the  previously  required  reporting  of  changes  in net  assets by
investment option for participant directed investments.

Use of Estimates
The  preparation  of  financial   statements,   in  conformity  with  accounting
principles generally accepted in the United States,  requires management to make
estimates  and  assumptions  that  affect  the  reported  amounts  of assets and
liabilities  and disclosure of contingent  assets and liabilities at the date of
the  financial  statements,  as  well  as  reported  amounts  of  additions  and
deductions during the reporting  period.  Actual results could differ from those
estimates.

Investment Valuation and Income Recognition
The Plan's investments are stated at fair value. Shares of registered investment
companies are valued at quoted market prices which represent the net asset value
of shares held by the Plan at year-end. Units of the Vanguard Retirement Savings
Trust (a  common/collective  trust) are  valued at the net asset  value of units
held by the Plan at year-end.  The Company  stock fund is valued at its year-end
unit closing price  (comprised  of year-end  market price plus  uninvested  cash
position). Participant loans are valued at cost, which approximates fair value.


                                      -6-



CROWN CORK & SEAL COMPANY, INC. RETIREMENT THRIFT PLAN

Notes to Financial Statements
- --------------------------------------------------------------------------------

Purchases and sales of investments are recorded on a trade-date basis.  Interest
income is accrued when earned.  Dividend  income is recorded on the  ex-dividend
date. Capital gain distributions are included in dividend income.

Payment of Benefits
Benefits are recorded when paid.

NOTE 3 - INVESTMENTS

During  1999 and 1998,  the Plan's  investments  (including  gains and losses on
investments  bought  and sold,  as well as held  during  the  year)  appreciated
(depreciated) in value as follows:

                                               1999                 1998
                                               ----                 ----

Registered investment companies            $  7,542,425         $  3,426,836
Common stock                                   (408,633)            (767,618)
                                           -------------        -------------
                                           $  7,133,792         $  2,659,218
                                           =============        =============

All investments are participant-directed.



NOTE 4 - RELATED PARTY TRANSACTIONS

The  Plan  invests  in  shares  of   registered   investment   companies  and  a
common/collective  trust  managed by an affiliate of VFTC.  VFTC acts as trustee
for only those  investments  as defined  by the Plan.  The Plan also  invests in
shares of the Company's stock through the Crown Cork & Seal Company,  Inc. Stock
Fund. Transactions in such investments qualify as party-in-interest transactions
and are exempt from the prohibited transaction rules.

NOTE 5 - TAX STATUS

The Internal Revenue Service has determined and informed the Company by a letter
dated  February  13,  1996  that the Plan and  related  trust  are  designed  in
accordance with applicable  sections of the Internal  Revenue Code ("IRC").  The
Plan has been amended since receiving the  determination  letter.  However,  the
Plan  administrator and the Plan's tax counsel believe that the Plan is designed
and is currently being operated in compliance  with the applicable  requirements
of the IRC.


                                      -7-



                     Additional Information
                     Required for Form 5500



CROWN CORK & SEAL COMPANY, INC. RETIREMENT                        Schedule I
THRIFT PLAN
Schedule of Assets Held for Investment Purposes
As of December 31, 1999
- --------------------------------------------------------------------------------

Crown Cork & Seal Company, Inc. Retirement Thrift Plan, EIN 23-1526444

Form 5500, Schedule H, Part IV, Line i


     Identity of Issue                                                Investment Type               Current Value
- -----------------------------------------------------------------------------------------------------------------
                                                                                              

*    Vanguard 500 Index Fund                                   Registered Investment Company        $ 42,456,089
*    Vanguard Balanced Index                                   Registered Investment Company           8,562,339
*    Vanguard Explorer Fund                                    Registered Investment Company           6,017,959
*    Vanguard International Growth Fund                        Registered Investment Company           3,567,039
*    Vanguard Total Bond Market Index                          Registered Investment Company           5,434,830
*    Vanguard Retirement Savings Trust                         Common/Collective Trust                24,974,650
*    Crown Cork & Seal Company, Inc.                           Common Stock                            1,199,100
*    Crown Cork & Seal Company, Inc. Retirement Thrift Plan    Participant Loans (7% - 9.5%)           1,888,304
                                                                                                    ------------
Total assets held for investment purposes                                                           $ 94,100,310
                                                                                                    ============
<FN>
* Party in Interest
</FN>










                                      -8-