Filer:  Thermo Electron Corporation
                                      Pursuant  to Rule 425 under the Securities
                                  Act of 1933 and  deemed filed pursuant to Rule
                                  14a-12 of the Securities Exchange Act of 1934
                                     Subject Company:  Thermo Cardiosystems Inc.
                               Subject Company Exchange Act File No.:  001-10114


        Thermo Electron Plans to Resubmit Antitrust Filings Related to
                 Merger of Thermo Cardiosystems and Thoratec

WALTHAM,  Mass.,  November  29, 2000 - Thermo  Electron  Corporation  (NYSE:TMO)
announced today that it has withdrawn and is resubmitting its  Hart-Scott-Rodino
antitrust  filings with the Federal Trade  Commission  and Department of Justice
regarding  the  proposed  merger  of its  Thermo  Cardiosystems  Inc.  (ASE:TCA)
subsidiary and Thoratec Laboratories Corporation (NASDAQ:THOR).

      The resubmission  will start a new 30-day waiting period that would expire
at the end of December,  unless the FTC shortens or extends the waiting  period.
The company's refiling will provide the FTC with additional time to complete its
investigation  of the  competitive  implications  of the  proposed  transaction.
Assuming the transaction  clears antitrust review, the companies still expect to
complete the merger during the first quarter of 2001.

      The proposed transaction was announced on October 3, 2000. Under the terms
of the  agreement,  each issued and  outstanding  share of Thermo  Cardiosystems
stock will be exchanged  for 0.835 shares of newly issued  Thoratec  stock.  The
transaction  is subject  to the  approval  by  shareholders  of both  companies,
regulatory approval, and usual conditions.

      Thermo  Electron  Corporation  is a leading  provider  of  analytical  and
monitoring instruments used in a broad range of applications, from life sciences
research to  telecommunications  to food,  drug,  and  beverage  production.  In
addition,  Thermo  Electron  serves the  healthcare  market  through a family of
medical  companies,  and is a major  producer  of paper  recycling  systems  and
provides fiber-recovery  products. As announced on January 31, 2000, the company
has initiated a major  reorganization  that would transform it into one publicly
traded entity focused on its core instruments  business.  The company's  medical
products and paper recycling  businesses will be spun off as dividends to Thermo
Electron shareholders. More information is available at http://www.thermo.com.

Other Important Information:
The proposed merger between Thermo  Cardiosystems and Thoratec is described in a
preliminary  joint  proxy  statement/prospectus  that  has been  filed  with the
Securities  and Exchange  Commission.  You should read this document  because it
contains important information about the transaction, including the participants
in the  transaction.  You can obtain the joint  proxy  statement/prospectus  and
other  documents that will be filed with the Securities and Exchange  Commission
for free when they are available on the Securities and Exchange Commission's Web
site at  http://www.sec.gov.  Also,  if you  write  us or  call us at the  below
address and phone number, we will send you the joint proxy  statement/prospectus
for free when it is available.

You can call us at (781) 622-1111, or write to us at:

      Investor Relations Department
      Thermo Electron Corporation
      81 Wyman Street, P.O. Box 9046
      Waltham, MA 02454-9046




                                     -more-





The following constitutes a "Safe Harbor" statement under the Private Securities
Litigation  Reform Act of 1995:  This  press  release  contains  forward-looking
statements that involve a number of risks and  uncertainties.  Important factors
that could cause actual  results to differ  materially  from those  indicated by
such  forward-looking  statements are set forth under the heading "Risk Factors"
in the company's Amendment No. 2 to Registration Statement on Form S-4 [Reg. No.
333-35478]  filed with the Securities and Exchange  Commission on June 27, 2000.
These include  risks and  uncertainties  relating to: the  company's  ability to
complete its corporate reorganization, the need for a favorable Internal Revenue
Service ruling regarding planned spin-offs of certain subsidiaries, divestitures
planned as part of the reorganization, integration of the instrument businesses,
issuance  of   significant   amounts  of  additional   shares  as  part  of  the
reorganization,  liquidity and prospective performance of the subsidiaries to be
spun off,  guarantees of obligations of the  subsidiaries  to be spun off, stock
price volatility,  goodwill acquired by the company, internal growth, the effect
of  exchange  rate  fluctuations  on  the  company's  significant  international
operations,   the  need  to  develop  new  products  and  adapt  to  significant
technological  change,  changes in governmental  regulations,  and dependence of
demand on capital spending and government funding policies.


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