1
                                    Filed Pursuant to Rule 424(b)(5)
                                    File Nos. 333-67883 and 333-65659
 
PROSPECTUS SUPPLEMENT
(To Prospectuses Dated October 30, 1998 and December 1, 1998)
 
                           3,700,000 ORDINARY SHARES
 
                        [FLEXTRONICS INTERNATIONAL LOGO]
 
                                ORDINARY SHARES
 
     Of the 3,700,000 Ordinary Shares being offered, Flextronics International
Ltd. is offering 2,700,000 Ordinary Shares, and selling shareholders are
offering 1,000,000 Ordinary Shares. On December 4, 1998, the last reported sale
price of the Ordinary Shares on the Nasdaq National Market was $75 3/4 per
share.
 
     The Ordinary Shares are listed on the Nasdaq National Market under the
symbol "FLEX."
 
     INVESTING IN THE ORDINARY SHARES INVOLVES A HIGH DEGREE OF RISK. SEE "RISK
FACTORS" BEGINNING ON PAGE S-3 OF THIS PROSPECTUS SUPPLEMENT.
 


- ----------------------------------------------------------------------------------
- ----------------------------------------------------------------------------------
                                                         Per Share       Total
- ----------------------------------------------------------------------------------
                                                                
Offering Price                                            $72.50      $268,250,000
Discounts and Commissions to Underwriter                  $  .50      $  1,850,000
Offering Proceeds to Company                              $72.00      $194,400,000
Offering Proceeds to Selling Shareholders                 $72.00      $ 72,000,000
- ----------------------------------------------------------------------------------
- ----------------------------------------------------------------------------------

 
     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved these securities or determined if this
Prospectus Supplement is truthful or complete. Any representation to the
contrary is a criminal offense.
 
     NationsBanc Montgomery Securities LLC expects to deliver the Ordinary
Shares to investors on December 10, 1998.
 
                     NATIONSBANC MONTGOMERY SECURITIES LLC
 
                        -------------------------------
 
                                December 7, 1998
   2
 
                           FORWARD-LOOKING STATEMENTS
 
     This Prospectus Supplement and the accompanying Prospectuses (including the
documents incorporated by reference in the Prospectuses) contain forward-looking
statements regarding our plans, expectations, estimates and beliefs. Our actual
results could differ materially from those discussed in, or implied by, these
forward-looking statements. Forward-looking statements are identified by words
such as "believes," "anticipates," "expects," "intends," "plans," "will," "may"
and other similar expressions. In addition, any statements which refer to
expectations, projections or other characterizations of future events or
circumstances are forward-looking statements. Forward-looking statements in
these documents include, but are not necessarily limited to, those relating to:
 
     - ability to carry out our strategies;
 
     - growth in sales;
 
     - facilities expansion;
 
     - potential acquisitions;
 
     - adoption of outsourcing by OEMs;
 
     - becoming an integral part of customer operations;
 
     - ability to win new customer contracts;
 
     - Year 2000 compliance;
 
     - implementation of our new management information system;
 
     - tax matters; and
 
     - currency fluctuations.
   3
 
                         PROSPECTUS SUPPLEMENT SUMMARY
 
     You should read the following summary together with the more detailed
information appearing elsewhere in this Prospectus Supplement and in the
accompanying Prospectuses (including the documents incorporated by reference in
the Prospectuses).
 
                                  THE COMPANY
 
     Flextronics is a leading provider of advanced electronics manufacturing
services to original equipment manufacturers in the telecommunications,
networking, computer, consumer electronics and medical device industries. We
provide a wide range of integrated services, from initial product design to
volume production and fulfillment. Our manufacturing services range from printed
circuit board fabrication and assembly to complete product assembly and test. We
believe that we have developed particular strengths in advanced interconnect,
miniaturization and packaging technologies. In addition, we provide advanced
engineering services, including product design, PCB layout, quickturn
prototyping and test development. Throughout the production process, we offer
logistics services, such as materials procurement, inventory management,
packaging and distribution.
 
     Through a combination of internal growth and acquisitions, we have become
the fourth largest provider of electronics manufacturing services, with net
sales of more than $1.4 billion in the 12 months ended September 25, 1998. We
believe that our size, global presence and expertise enable us to win large
outsourced manufacturing programs from leading OEMs. We offer a complete and
flexible manufacturing solution that provides accelerated time-to-market and
time-to-volume production, as well as reduced production costs. By working
closely with customers throughout the design, manufacturing and distribution
process, and by offering highly responsive services, we believe that we can
become an integral part of their operations.
 
     Our customers include industry leaders such as Alcatel, Bay Networks,
Cisco, Compaq, Ericsson, Microsoft, Nokia, Philips, Sony and 3Com. In addition,
we recently entered into relationships with a number of new customers, including
Eastman Kodak, Hewlett-Packard, Intel, Qualcomm and Rockwell. Due to our focus
on high growth technology sectors, our prospects are influenced by certain major
trends, such as the buildout of the communications and Internet infrastructure,
the proliferation of wireless devices and other trends in electronics
technologies. In addition, our growth is driven by the accelerating pace at
which leading OEMs are adopting outsourcing as a core business strategy.
 
     We have established an extensive network of manufacturing facilities in the
world's major electronics markets -- Asia, the Americas and Europe -- to serve
the increased outsourcing needs of both multinational and regional OEMs. We
strategically locate facilities near our customers' end markets and have located
fully integrated, high volume manufacturing facilities in low cost regions
worldwide. We have established industrial parks in China, Hungary and Mexico and
plan to develop an industrial park in Brazil. These self-contained facilities
provide a total manufacturing and fulfillment solution from a single site by
locating manufacturing and distribution operations and suppliers together. This
integrated approach to production and distribution benefits our customers by
reducing logistical barriers and costs, improving supply-chain management,
increasing flexibility, lowering transportation costs and reducing turnaround
times.
 
     Since March 31, 1997, we have increased overall capacity by approximately
1.6 million square feet through internal growth and acquisitions. As a result,
we have grown to over 2.7 million square feet of capacity on four continents. We
plan to continue to expand through internal growth, and to consider strategic
acquisitions from time to time as appropriate.
 
                                       S-1
   4
 
                                  THE OFFERING
 

                                            
Ordinary Shares offered:
  By Flextronics.............................  2,700,000
  By selling shareholders....................  1,000,000
                                               ---------
          Total..............................  3,700,000
Ordinary Shares to be outstanding after the
  offering...................................  23,319,411 shares(1)
Use of proceeds..............................  Repayment of debt, funding capital
                                               expenditures and general corporate purposes,
                                               including working capital.
Nasdaq National Market symbol................  FLEX

 
                   SUMMARY CONSOLIDATED FINANCIAL INFORMATION
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 


                                                                                                      SIX MONTHS ENDED
                                                        YEAR ENDED MARCH 31,                    -----------------------------
                                       ------------------------------------------------------   SEPTEMBER 30,   SEPTEMBER 25,
                                         1994       1995       1996       1997        1998          1997            1998
                                       --------   --------   --------   --------   ----------   -------------   -------------
                                                                                                         (UNAUDITED)
                                                                                           
CONSOLIDATED STATEMENT
  OF OPERATIONS DATA:
  Net sales..........................  $131,345   $292,149   $572,045   $640,007   $1,113,071     $487,013        $799,027
  Income (loss) from operations......     3,835     10,099     (5,375)    20,072       42,678       21,587          37,291
  Net income (loss)..................     2,151      5,881    (14,146)    11,620       19,913       13,168          24,520
  Diluted net income (loss) per
    share(2).........................  $   0.28   $   0.40   $  (0.92)  $   0.67   $     1.04     $   0.75        $   1.13
  Weighted average Ordinary Shares
    and equivalents
    outstanding -- diluted(2)........     7,730     14,882     15,436     17,328       19,097       17,663          21,669

 


                                                                  SEPTEMBER 25, 1998
                                                              --------------------------
                                                               ACTUAL     AS ADJUSTED(3)
                                                              --------    --------------
                                                                     (UNAUDITED)
                                                                    
CONSOLIDATED BALANCE SHEET DATA:
  Working capital...........................................  $ 96,723       $290,723
  Total assets..............................................   799,579        993,579
  Long-term debt and capital lease obligations, excluding
    current portion.........................................   188,740        188,740
  Shareholders' equity......................................   246,890        440,890

 
- ---------------
(1) Based on the number of Ordinary Shares actually outstanding as of September
    25, 1998. Excludes a total of 3,686,838 Ordinary Shares subject to
    outstanding options or reserved for issuance under our 1993 Share Option
    Plan, 1997 Interim Option Plan, 1998 Interim Option Plan and 1997 Employee
    Share Purchase Plan.
 
(2) These share and per share amounts do not give effect to our recently
    announced two-for-one stock split to be effected in the form of a bonus
    issue (the Singapore equivalent of a stock dividend) and to be paid to our
    shareholders of record as of December 22, 1998.
 
(3) Includes estimated offering expenses of $400,000.
 
     In this Prospectus Supplement and in the accompanying Prospectuses,
references to "U.S. dollars" and "$" are to United States currency, and
references to "Singapore dollars" and "S$" are to Singapore currency.
 
                                       S-2
   5
 
                                  RISK FACTORS
 
     This offering involves a high degree of risk. You should carefully consider
the risks described below and the other information in this Prospectus
Supplement and the accompanying Prospectuses (including the information
incorporated by reference in the accompanying Prospectuses and the Risk Factors
contained therein) before deciding to invest in our Ordinary Shares.
 
RISKS OF EXPANSION OF OPERATIONS
 
     We have grown rapidly in recent periods, and this growth may not continue.
Internal growth will require us to develop new customer relationships and expand
existing ones, improve our operational and information systems and further
expand our manufacturing capacity.
 
     We plan to further expand our manufacturing capacity by expanding our
facilities and by adding new equipment. Such expansion involves significant
risks. For example:
 
     - we may not be able to attract and retain the management personnel and
       skilled employees necessary to support expanded operations;
 
     - we may not efficiently and effectively integrate new operations, expand
       existing ones and manage geographically dispersed operations;
 
     - we may incur cost overruns;
 
     - we may encounter construction delays, equipment delays or shortages,
       labor shortages and disputes and production start-up problems that could
       adversely affect our growth and our ability to meet customers' delivery
       schedules; and
 
     - we may not be able to obtain funds for this expansion, and we may not be
       able to obtain loans or operating leases with attractive terms.
 
     In addition, we expect to incur new fixed operating expenses associated
with our expansion efforts, including substantial increases in depreciation
expense and rental expense, that will increase our cost of sales. If our
revenues do not increase sufficiently to offset these expenses, our operating
results would be adversely affected. Our expansion, both through acquisitions
and internal growth, has contributed to our incurring significant accounting
charges and experiencing volatility in our operating results. We may continue to
experience volatility in operating results in connection with future expansion
efforts.
 
RISKS OF ACQUISITIONS
 
     Our acquisitions during the last two fiscal years represented a significant
expansion of our operations. Acquisitions involve a number of risks and
challenges, including:
 
     - diversion of management's attention;
 
     - the need to integrate acquired operations;
 
     - potential loss of key employees and customers of the acquired companies;
 
     - lack of experience operating in the geographic market of the acquired
       business; and
 
     - an increase in our expenses and working capital requirements.
 
     To integrate acquired operations, we must implement our management
information systems and operating systems and assimilate and manage the
personnel of the acquired operations. The difficulties of this integration may
be further complicated by geographic distances. The integration of acquired
businesses may not be successful and could result in disruption to other parts
of our business.
 
     Any of these and other factors could adversely affect our ability to
achieve anticipated levels of profitability at acquired operations or realize
other anticipated benefits of an acquisition. Furthermore, any
 
                                       S-3
   6
 
future acquisitions may require debt or equity financing, which could increase
our leverage or be dilutive to our existing shareholders. No assurance can be
given that we will consummate any acquisitions in the future.
 
VARIABILITY OF CUSTOMER REQUIREMENTS AND OPERATING RESULTS
 
     Electronics manufacturing service providers must provide increasingly rapid
product turnaround for their customers. We generally do not obtain firm,
long-term purchase commitments from our customers, and over the past few years
we have experienced reduced lead-times in customer orders. Customers may cancel
their orders, change production quantities or delay production for a number of
reasons. Cancellations, reductions or delays by a significant customer or by a
group of customers would adversely affect our results of operations. In addition
to the variable nature of our operating results due to the short-term nature of
our customers' commitments, other factors may contribute to significant
fluctuations in our results of operations. These factors include:
 
     - the timing of customer orders;
 
     - the volume of these orders relative to our capacity;
 
     - market acceptance of customers' new products;
 
     - changes in demand for customers' products and product obsolescence;
 
     - the timing of our expenditures in anticipation of future orders;
 
     - our effectiveness in managing manufacturing processes;
 
     - changes in the cost and availability of labor and components;
 
     - changes in our product mix;
 
     - changes in economic conditions;
 
     - local factors and events that may affect our production volume (such as
       local holidays); and
 
     - seasonality in customers' product requirements.
 
     We make significant decisions, including the levels of business that we
will seek and accept, production schedules, component procurement commitments,
personnel needs and other resource requirements, based on our estimates of
customer requirements. The short-term nature of our customers' commitments and
the possibility of rapid changes in demand for their products reduces our
ability to estimate accurately future customer requirements. On occasion,
customers may require rapid increases in production, which can stress our
resources and reduce margins. Although we have increased our manufacturing
capacity and plan further increases, there can be no assurance we will have
sufficient capacity at any given time to meet our customers' demands. In
addition, because many of our costs and operating expenses are relatively fixed,
a reduction in customer demand can adversely affect our gross margins and
operating income.
 
CUSTOMER CONCENTRATION; DEPENDENCE ON ELECTRONICS INDUSTRY
 
     Our five largest customers accounted for approximately 64% of consolidated
net sales in the six months ended September 25, 1998, compared to approximately
58% in the six months ended September 30, 1997. Our largest customers during
fiscal 1998 were Ericsson and Philips Electronics, accounting for approximately
26% and 13% of consolidated net sales, respectively. The identity of our
significant customers has varied from year to year, and our significant
customers may not continue to purchase services from us at current levels, if at
all. Significant reductions in sales to any of these customers, or the loss of
major customers, would have a material and adverse effect on us. We may not be
able to replace such reductions or losses with new business in a timely manner.
See "-- Variability of Customer Requirements and Operating Results."
 
     Our largest customer in fiscal 1998, and the six months ended September 25,
1998, has been Ericsson. Our agreement with Ericsson contains cost reduction
targets and price limitations and imposes certain manufacturing quality
requirements. We may not be able to sustain acceptable levels of profitability
under this
 
                                       S-4
   7
 
agreement or reduce costs and prices to Ericsson over time as contemplated by
this agreement. In addition, the agreement contains certain operating and
financial covenants, and a material breach by us of any of the terms of the
agreement could allow Ericsson to repurchase the facilities sold to us by
Ericsson in Karlskrona, Sweden (the "Karlskrona Facilities") at book value, or
to cancel outstanding purchase orders or terminate the agreement. Without
Ericsson's consent, we may not use the Karlskrona Facilities for Ericsson's
competitors, or enter into any transactions that could adversely affect our
ability to continue to supply products and services to Ericsson under the
agreement or our ability to reduce costs and prices to Ericsson.
 
     Factors affecting the electronics industry in general could have a material
adverse effect on our customers and, as a result, on us. Such factors include:
 
     - the inability of our customers to adapt to rapidly changing technology
       and evolving industry standards, which results in short product life
       cycles;
 
     - the inability of our customers to develop and market their products, some
       of which are new and untested. If customers' products become obsolete or
       fail to gain widespread commercial acceptance, our business may be
       materially and adversely affected; and
 
     - recessionary periods in our customers' markets.
 
REPLACEMENT OF MANAGEMENT INFORMATION SYSTEMS; YEAR 2000 COMPLIANCE
 
     We are in the process of replacing our management information system with a
new enterprise management information system that is designed to provide
enhanced functionality. This new system will significantly affect many aspects
of our business, including our manufacturing, sales and marketing and accounting
functions, and the successful implementation of this system will be important to
our future growth. We have implemented this new information system in certain
facilities in Europe and North America and anticipate that the installation of
the new system will be completed by September 1999, but it could be delayed.
Significant disruption in operations may result from the implementation of the
new system. Delays in the implementation of the new system or disruption
resulting from it could adversely affect our ability to meet customers'
production schedules and our ability to access timely financial and operating
information.
 
     We believe that this new enterprise management information system will be
Year 2000 compliant. However, there can be no assurance that the new system will
be Year 2000 compliant or that it will be implemented by January 1, 2000. If the
new system is not Year 2000 compliant or is not implemented by January 1, 2000,
we could be materially and adversely affected. The Year 2000 issue also could
affect our infrastructure and production lines. We have made substantial Year
2000 compliant equipment additions and upgrades in recent years and believe that
the impact of a problem affecting our infrastructure or production lines would
be minor. However, we have not completed sufficient testing to date to fully
validate the readiness of our equipment. We plan to have additional testing
completed during fiscal 1999 to reasonably ensure Year 2000 readiness. In
addition, we are surveying our significant customers and suppliers regarding
their Year 2000 compliance, but this undertaking has not been completed. We
could be adversely affected by disruptions in our customers' and suppliers'
businesses due to Year 2000 problems.
 
RISKS OF INCREASED TAXES
 
     We have structured our operations in a manner designed to maximize income
in countries where tax incentives have been extended to encourage foreign
investment or where income tax rates are low. Our taxes could increase if these
tax incentives are not renewed upon expiration or tax rates applicable to us are
increased. Substantially all of the products manufactured by our Asian
subsidiaries are sold to customers based in North America and Europe. We believe
that profits from our Asian operations are not sufficiently connected to
jurisdictions in North America or Europe to give rise to income taxation there.
However, tax authorities in jurisdictions in North America and Europe could
challenge the manner in which profits are allocated among our subsidiaries, and
we may not prevail in any such challenge. If our Asian profits became subject to
income taxes in such other jurisdictions, our worldwide effective tax rate could
increase.
 
                                       S-5
   8
 
SIGNIFICANT LEVERAGE
 
     Our level of indebtedness presents risks to investors, including:
 
     - the possibility that we may be unable to generate cash sufficient to pay
       the principal of and interest on the indebtedness when due;
 
     - making us more vulnerable to economic downturns;
 
     - limiting our ability to pursue new business opportunities; and
 
     - reducing our flexibility in responding to changing business and economic
       conditions.
 
RISKS OF COMPETITION
 
     The electronics manufacturing services industry is extremely competitive
and includes hundreds of companies, several of which have achieved substantial
market share. Current and prospective customers also evaluate our capabilities
against the merits of internal production. Certain of our competitors, including
Solectron Corporation and SCI Systems, have substantially greater market shares
than Flextronics and substantially greater manufacturing, financial, research
and development and marketing resources. In recent years, many participants in
the industry, including us, have substantially expanded manufacturing capacity.
If overall demand for contract manufacturing services should decrease, this
increased capacity could result in substantial pricing pressures, which could
adversely affect our operating results.
 
RISKS OF INTERNATIONAL OPERATIONS
 
     The geographical distances between Asia, the Americas and Europe create a
number of logistical and communications challenges. Our manufacturing operations
are located in a number of countries, including Austria, Brazil, China, Hungary,
Malaysia, Mexico, Sweden, the United Kingdom and the United States. As a result,
we are affected by economic and political conditions in those countries,
including:
 
     - fluctuations in the value of currencies;
 
     - changes in labor conditions;
 
     - longer payment cycles;
 
     - greater difficulty in collecting accounts receivable;
 
     - burdens and costs of compliance with a variety of foreign laws;
 
     - political and economic instability;
 
     - increases in duties and taxation;
 
     - imposition of restrictions on currency conversion or the transfer of
       funds;
 
     - limitations on imports or exports;
 
     - expropriation of private enterprises; and
 
     - reversal of the current policies (including favorable tax and lending
       policies) encouraging foreign investment or foreign trade by our host
       countries.
 
     The attractiveness of our services to our U.S. customers can be affected by
changes in U.S. trade policies, such as "most favored nation" status and trade
preferences for certain Asian nations. For example, trade preferences extended
by the United States to Malaysia in recent years were not renewed in 1997. In
addition, some countries in which we operate, such as Brazil, Mexico and
Malaysia, have experienced periods of slow or negative growth, high inflation,
significant currency devaluations and limited availability of foreign exchange.
Furthermore, in countries such as Mexico and China, governmental authorities
exercise significant influence over many aspects of the economy, and their
actions could have a significant effect on Flextronics. Finally, we could be
adversely affected by inadequate infrastructure, including lack of adequate
power and water supplies, transportation, raw materials and parts in countries
in which we operate.
 
                                       S-6
   9
 
     Risks Relating to China. Under its current leadership, the Chinese
government has been pursuing economic reform policies. There can be no assurance
that the Chinese government will continue to pursue such policies, or that such
policies will be successful if pursued. In addition, China does not have a
comprehensive and highly developed system of laws, and enforcement of laws and
contracts is uncertain. The United States annually reconsiders the renewal of
most favored nation trading status for China. China's loss of most favored
nation status could adversely affect us by increasing the cost to U.S. customers
of products manufactured by us in China.
 
     Risks Relating to Hungary. Hungary has undergone significant political and
economic change in recent years. Political, economic, social and other
developments, and changes in laws could have a material and adverse effect on
our business. Annual inflation and interest rates in Hungary have historically
been much higher than those in Western Europe. Exchange rate policies have not
always allowed for the free conversion of currencies at the market rate. Laws
and regulations in Hungary have been, and continue to be, substantially revised
during its transition to a market economy. As a result, laws and regulations may
be applied inconsistently. Also, in some circumstances, it may not be possible
to obtain the legal remedies provided for under those laws and regulations in a
reasonably timely manner, if at all.
 
     Risks Relating to Brazil. During the past several years, the Brazilian
economy has been affected by significant intervention by the Brazilian
government. The Brazilian government has changed monetary, credit, tariff and
other policies to influence the course of Brazil's economy. The Brazilian
government's actions to control inflation and effect other policies have often
involved wage, price and exchange controls as well as other measures such as
freezing bank accounts and imposing capital controls.
 
RISKS OF CURRENCY FLUCTUATIONS AND HEDGING OPERATIONS
 
     With the acquisitions of the Karlskrona Facilities, Neutronics and Conexao,
a significant portion of our business is conducted in the Swedish kronor,
Austrian schilling and Brazilian real, respectively. In addition, some of our
costs, such as payroll and rent, are denominated in currencies such as the
Singapore dollar, the Hong Kong dollar, the Malaysian ringgit, the Hungarian
forint, the Mexican peso, and the British pound, as well as the kronor, the
schilling and the real. In recent years, the Hungarian forint, Brazilian real
and Mexican peso have experienced significant devaluations. Changes in exchange
rates between these and other currencies and the U.S. dollar will affect our
cost of sales and operating margins. We cannot predict the impact of future
exchange rate fluctuations. Our European and Latin American operations use
financial instruments, primarily forward purchase contracts, to hedge certain
fixed Japanese yen, German deutschmark, U.S. dollar, and other foreign currency
commitments arising from trade accounts payable and fixed purchase obligations.
Because we hedge only fixed obligations, we do not expect that these hedging
activities will have a material effect on our results of operations or cash
flows. However, our hedging activities may be unsuccessful, and we may change or
reduce our hedging activities in the future.
 
DEPENDENCE ON KEY PERSONNEL
 
     Our success depends to a large extent upon the continued services of our
key executives and skilled personnel. Generally, our employees are not bound by
employment or non-competition agreements, and there can be no assurance that we
will retain our officers and key employees. We could be materially and adversely
affected by the loss of such personnel.
 
LIMITED AVAILABILITY OF COMPONENTS
 
     A substantial majority of our net sales are derived from turnkey
manufacturing in which we are responsible for procuring materials, which
typically results in our bearing the risk of component price increases. At
various times, there have been shortages of certain electronics components.
Component shortages could result in manufacturing and shipping delays or higher
prices, which could have a material and adverse effect on us.
 
                                       S-7
   10
 
ENVIRONMENTAL COMPLIANCE RISKS
 
     We are subject to a variety of environmental regulations relating to the
use, storage, discharge and disposal of hazardous chemicals. Although we believe
that our facilities are currently in material compliance with applicable
environmental laws, there can be no assurances that violations will not occur.
The costs and penalties that could result from a violation of environmental laws
could materially adversely affect us.
 
SHARES ELIGIBLE FOR FUTURE SALE
 
     On October 30, 1998, Flextronics filed a registration statement for the
public resale of up to 3,262,403 Ordinary Shares with the Securities and
Exchange Commission. The registered shares were issued by Flextronics during
fiscal 1998 in connection with various acquisitions. While the selling
shareholders are selling 1,000,000 of such shares in this offering, up to
2,262,403 of such freely-transferable shares will remain available for sale in
the open market after the completion of this offering. Sales of such shares in
the public market could adversely affect the market price of the Ordinary
Shares.
 
VOLATILITY OF MARKET PRICE OF ORDINARY SHARES
 
     The stock market in recent years has experienced significant price and
volume fluctuations that have affected the market prices of technology
companies. Such fluctuations have often been unrelated to or disproportionately
impacted by the operating performance of such companies. The market for the
Ordinary Shares may be subject to similar fluctuations. Factors such as
fluctuations in our operating results, announcements of technological
innovations or events affecting other companies in the electronics industry,
currency fluctuations and general market conditions may have a significant
effect on the market price of the Ordinary Shares.
 
                                   DIVIDENDS
 
     Since inception, Flextronics has not declared or paid any cash dividends on
its Ordinary Shares, and our credit facility prohibits the payment of cash
dividends without the lenders' prior consent. The terms of our senior
subordinated notes also restrict our ability to pay cash dividends. Flextronics
anticipates that all earnings in the foreseeable future will be retained to
finance the continuing development of its business.
 
                                USE OF PROCEEDS
 
     We estimate that the net proceeds from the sale of the 2,700,000 Ordinary
Shares offered by us hereby will be approximately $194.0 million, at the public
offering price of $72 1/2 per share and after deducting the estimated
underwriting discounts and commissions and estimated offering expenses. We
intend to use the net proceeds from this offering to repay debt, to fund capital
expenditures and to meet our working capital requirements. We anticipate using a
portion of the net proceeds from this offering to repay the outstanding
revolving credit loans under our credit facility (approximately $39.5 million as
of September 25, 1998). These loans currently bear interest at a weighted
average interest rate of 6.67% per annum. A portion of the net proceeds may be
used to acquire or invest in complementary businesses. We have no current plans,
agreements or commitments with respect to any such acquisition, and we are not
currently engaged in any negotiations with respect to any such transaction.
Until the net proceeds have been used, they will be invested in short-term
marketable securities.
 
                                       S-8
   11
 
                         PRICE RANGE OF ORDINARY SHARES
 
     The Ordinary Shares are traded on the Nasdaq National Market under the
symbol "FLEX." The following table shows the high and low closing sale prices of
the Company's Ordinary Shares since the beginning of our 1997 fiscal year.
 


                                                              HIGH        LOW
                                                              ----        ---
                                                                    
Fiscal 1997
  First Quarter.............................................  $39         $25
  Second Quarter............................................  $28 1/4     $17
  Third Quarter.............................................  $37 1/4     $21
  Fourth Quarter............................................  $29 3/4     $19 5/8
Fiscal 1998
  First Quarter.............................................  $27         $17 1/2
  Second Quarter............................................  $47 3/8     $26 3/8
  Third Quarter.............................................  $49 1/2     $29
  Fourth Quarter............................................  $47 7/8     $32
Fiscal 1999
  First Quarter.............................................  $51 1/8     $41 1/8
  Second Quarter............................................  $47 1/2     $22
  Third Quarter (through December 4, 1998)..................  $75 3/4     $28

 
     On December 4, 1998, the closing sale price of the Ordinary Shares was
$75 3/4 per share. Flextronics has declared a bonus issue, the Singapore
equivalent of a stock dividend, of one new Ordinary Share for each Ordinary
Share outstanding to be paid to shareholders of record as of December 22, 1998.
 
                                 CAPITALIZATION
 
     The following table sets forth the unaudited capitalization of Flextronics
as of September 25, 1998 (i) on an actual basis, and (ii) as adjusted to give
effect to the sale of the 2,700,000 Ordinary Shares offered by Flextronics
hereby at the public offering price of $72 1/2 per share and after deducting the
underwriting discounts and commissions and estimated offering expenses and the
application of the estimated net proceeds therefrom.
 


                                                                  SEPTEMBER 25, 1998
                                                              --------------------------
                                                               ACTUAL      AS ADJUSTED
                                                              --------    --------------
                                                                    (IN THOUSANDS)
                                                                    
Bank borrowings.............................................  $ 62,584       $ 23,110
                                                              ========       ========
Current portion of long-term debt and capital lease
  obligations...............................................  $ 18,168       $ 18,168
                                                              --------       --------
Long-term debt and capital lease obligations, excluding
  current portion...........................................  $188,740       $188,740
                                                              --------       --------
Shareholders' equity(1):
  Ordinary Shares, S$0.01 par value; 100,000,000 shares
     authorized, 20,619,411 shares issued and outstanding,
     23,319,411 shares issued and outstanding as adjusted...       135            151
  Additional paid-in capital................................   218,320        412,304
  Retained earnings.........................................    31,454         31,454
  Accumulated other comprehensive loss......................    (3,019)        (3,019)
                                                              --------       --------
          Total shareholders' equity........................   246,890        440,890
                                                              --------       --------
          Total capitalization..............................  $435,630       $629,630
                                                              ========       ========

 
- ---------------
(1) Based on the number of Ordinary Shares actually outstanding as of September
    25, 1998. Excludes a total of 3,686,838 Ordinary Shares subject to
    outstanding options or reserved for issuance under our 1993 Share Option
    Plan, 1997 Interim Option Plan, 1998 Interim Option Plan and 1997 Employee
    Share Purchase Plan.
 
                                       S-9
   12
 
                      SELECTED CONSOLIDATED FINANCIAL DATA
 
     The following selected consolidated financial data is qualified by
reference to, and should be read in conjunction with, the Consolidated Financial
Statements and the notes thereto, and "Management's Discussion and Analysis of
Financial Condition and Results of Operations" in our Form 10-K for the year
ended March 31, 1998 and in our Form 10-Q for the quarter ended September 25,
1998. The selected consolidated financial data for the fiscal years ended March
31, 1995, 1996, 1997 and 1998 and as of March 31, 1996, 1997 and 1998 has been
derived from the consolidated financial statements of Flextronics which were
audited by Arthur Andersen LLP, independent public accountants. The selected
consolidated financial data for the fiscal year ended March 31, 1994 and as of
March 31, 1994 and 1995 has been derived from the consolidated financial
statements of Flextronics which were audited by other auditors. The selected
consolidated financial data for the six months ended September 30, 1997 and
September 25, 1998 and as of September 25, 1998 are derived from unaudited
financial data and, in the opinion of management, include all adjustments,
consisting of only normal recurring adjustments, considered necessary for a fair
presentation. These historical results are not necessarily indicative of the
results to be expected in the future.
 


                                                                                                          SIX MONTHS ENDED
                                                          YEAR ENDED MARCH 31,                      -----------------------------
                                        --------------------------------------------------------    SEPTEMBER 30,   SEPTEMBER 25,
                                          1994       1995       1996        1997         1998           1997            1998
                                        --------   --------   --------    --------    ----------    -------------   -------------
                                                  (IN THOUSANDS EXCEPT PER SHARE DATA)                       (UNAUDITED)
                                                                                               
CONSOLIDATED STATEMENT OF OPERATIONS
  DATA:
  Net sales...........................  $131,345   $292,149   $572,045    $640,007    $1,113,071      $487,013        $799,027
  Cost of sales.......................   117,392    265,426    517,732     575,142     1,004,170       439,303         729,065
                                        --------   --------   --------    --------    ----------      --------        --------
  Gross margin........................    13,953     26,723     54,313      64,865       108,901        47,710          69,962
  Selling, general and
    administrative....................     8,667     15,771     28,138      36,277        53,695        24,370          30,910
  Goodwill and intangibles
    amortization......................       419        762      1,296       2,648         3,659         1,753           1,761
  Provision for excess facilities.....       830         --      1,254(1)    5,868(2)      8,869(3)         --              --
  Acquired in-process research and
    development.......................       202         91     29,000(1)       --            --            --              --
                                        --------   --------   --------    --------    ----------      --------        --------
  Income (loss) from operations.......     3,835     10,099     (5,375)     20,072        42,678        21,587          37,291
  Merger-related expenses.............        --       (816)        --          --        (7,415)(3)         --             --
  Other expense, net..................    (1,446)    (1,814)    (4,924)     (6,425)      (13,092)       (6,761)         (9,429)
                                        --------   --------   --------    --------    ----------      --------        --------
  Income (loss) before income taxes...     2,389      7,469    (10,299)     13,647        22,171        14,826          27,862
  Provision for income taxes..........       654      1,588      3,847       2,027         2,258         1,658           3,342
  Extraordinary gain..................       416         --         --          --            --            --              --
                                        --------   --------   --------    --------    ----------      --------        --------
  Net income (loss)...................  $  2,151   $  5,881   $(14,146)   $ 11,620    $   19,913      $ 13,168        $ 24,520
                                        ========   ========   ========    ========    ==========      ========        ========
  Net income (loss) per share(4):
    Basic.............................  $   0.28   $   0.42   $  (0.92)   $   0.70    $     1.09      $   0.77        $   1.18
    Diluted...........................  $   0.28   $   0.40   $  (0.92)   $   0.67    $     1.04      $   0.75        $   1.13
  Weighted average Ordinary Shares
    used in computing per share
    amounts(4):
    Basic.............................     7,730     14,143     15,436      16,704        18,263        16,997          20,765
    Diluted...........................     7,730     14,882     15,436      17,328        19,097        17,663          21,669

 


                                                                              MARCH 31,                         SIX MONTHS ENDED
                                                         ----------------------------------------------------     SEPTEMBER 25,
                                                           1994       1995       1996       1997       1998           1998
                                                         --------   --------   --------   --------   --------   -----------------
                                                                            (IN THOUSANDS)                         (UNAUDITED)
                                                                                              
CONSOLIDATED BALANCE SHEET DATA:
  Working capital (deficit)............................  $ 30,669   $ 36,737   $ 25,527   $(30,245)  $124,536       $ 96,723
  Total assets.........................................   103,129    185,186    309,267    446,292    744,123        799,579
  Long-term debt and capital lease obligations,
    excluding current portion..........................     4,755      6,890     31,894     29,128    189,678        188,740
  Shareholders' equity.................................    46,703     68,433     85,571     99,345    214,809        246,890

 
- ---------------
(1) In fiscal 1996, Flextronics wrote off $29.0 million of in-process research
    and development associated with the acquisition of Astron and also recorded
    charges totaling $1.3 million for costs associated with the closing of one
    of Flextronics' Malaysian plants and its Shekou, China operations.
 
(2) In fiscal 1997, Flextronics incurred plant closing expenses totaling $5.9
    million in connection with closing its manufacturing facility in Texas,
    downsizing manufacturing operations in Singapore, writing off excess
    equipment and certain severance obligations.
 
(3) In fiscal 1998, Flextronics incurred plant closing expenses totaling $8.9
    million in connection with closing its manufacturing facility in Wales, UK.
    Flextronics also incurred $7.4 million of merger-related costs as a result
    of its fiscal 1998 acquisitions.
 
(4) These share and per share amounts do not give effect to our recently
    announced two-for-one stock split to be effected in the form of a bonus
    issue (the Singapore equivalent of a stock dividend) and to be paid to our
    shareholders of record as of December 22, 1998.
 
                                      S-10
   13
 
                                    BUSINESS
 
     Flextronics is a leading provider of advanced electronics manufacturing
services to original equipment manufacturers in the telecommunications,
networking, computer, consumer electronics and medical device industries. We
provide a wide range of integrated services, from initial product design to
volume production and fulfillment. Our manufacturing services range from printed
circuit board fabrication and assembly to complete product assembly and test. We
believe that we have developed particular strengths in advanced interconnect,
miniaturization and packaging technologies. In addition, we provide advanced
engineering services, including product design, PCB layout, quickturn
prototyping and test development. Throughout the production process, we offer
logistics services, such as materials procurement, inventory management,
packaging and distribution.
 
     Through a combination of internal growth and acquisitions, we have become
the fourth largest provider of electronics manufacturing services with revenues
of more than $1.4 billion through the 12 months ended September 25, 1998. We
believe that our size, global presence and expertise enable us to win large
outsourced manufacturing programs from leading multinational OEMs. We offer a
complete and flexible manufacturing solution that provides accelerated
time-to-market and time-to-volume production, as well as reduced production
costs. By working closely with customers throughout the design, manufacturing
and distribution process, and by offering highly responsive services, we believe
that we can become an integral part of their operations.
 
     Our customers include industry leaders such as Alcatel, Bay Networks,
Cisco, Compaq, Ericsson, Microsoft, Nokia, Philips, Sony and 3Com. In addition,
we recently entered into relationships with a number of new customers, including
Eastman Kodak, Hewlett-Packard, Intel, Qualcomm and Rockwell. Due to our focus
on high growth technology sectors, our prospects are influenced by certain major
trends, such as the buildout of the communications and Internet infrastructure,
the proliferation of wireless devices and other trends in electronics
technologies. In addition, our growth is driven by the accelerating pace at
which leading OEMs are adopting outsourcing as a core business strategy.
 
INDUSTRY OVERVIEW
 
     Many OEMs in the electronics industry are increasingly using electronics
manufacturing service providers in their business and manufacturing strategies
and are seeking to outsource a broad range of manufacturing and related
engineering services. Outsourcing allows OEMs to take advantage of the
manufacturing expertise and capital investments of electronics manufacturing
service providers, thereby enabling OEMs to concentrate on their core
competencies, such as product development, marketing and sales. OEMs utilize
electronics manufacturing service providers to enhance their competitive
position by:
 
     - reducing production costs;
 
     - accelerating time-to-market and time-to-volume production;
 
     - accessing advanced manufacturing and design capabilities;
 
     - reducing capital investment requirements and fixed overhead costs;
 
     - improving inventory management and purchasing power; and
 
     - accessing worldwide manufacturing capabilities.
 
     As a result of these factors, industry sources estimate that the overall
market for electronic manufacturing services has grown at an average annual rate
of 25% from 1988 to 1997, reaching an estimated $73 billion in 1997.
 
STRATEGY
 
     Our objective is to enhance our position as a top tier provider of advanced
electronics manufacturing services. Our strategy to meet this objective includes
the following key elements:
 
     Serve Major Markets From Strategic, Low Cost Regions. We have established
an extensive network of manufacturing facilities in the world's major
electronics markets -- Asia, the Americas and Europe -- to serve the increased
outsourcing needs of both multinational and regional OEMs. We strategically
locate
 
                                      S-11
   14
 
facilities near our customers' end markets and have located fully integrated,
high volume manufacturing facilities in low cost regions worldwide. By operating
in low cost areas, we are able to realize savings in lower labor, overhead, tax
and transportation costs, which we can pass on to our customers.
 
     Capitalize on Industrial Park Strategy. We have established large,
strategically located industrial parks in China, Hungary and Mexico, designed
for high volume production, and plan to develop a new industrial park in Brazil.
These self-contained facilities provide a total manufacturing and fulfillment
solution from a single site by locating manufacturing and distribution
operations and suppliers together. This integrated approach to production and
distribution benefits our customers by reducing logistical barriers and costs,
improving supply-chain management, increasing flexibility, lowering
transportation costs and reducing turnaround times.
 
     Establish Close Relationships with Customers. We believe we can become an
integral part of our customers' operations by working closely with them
throughout the design, manufacturing and distribution process, and by offering
flexible, highly responsive services. We believe we develop strong customer
relationships through a management approach which fosters rapid decision-making
and a customer service orientation that responds quickly to frequently changing
customer design specifications and production requirements. In many cases, we
closely integrate our information systems with those of our customers. This
customer-focused approach allows us to accelerate our customers' time-to-market
and time-to-volume production and helps them to respond quickly to change.
 
     Deliver Complete Manufacturing Solution. We believe OEMs are increasingly
requiring a wider range of advanced engineering and manufacturing services in
order to reduce their costs and accelerate their time to market. Building on our
integrated engineering and manufacturing capabilities, we provide services from
initial product design and test to final product assembly and distribution to
the OEMs' customers. In addition, our global network of industrial parks,
manufacturing and technology centers, regional manufacturing facilities and
product introduction centers provides customers with a scalable, flexible
solution to support their needs as their products move from design and initial
introduction to high volume production and distribution.
 
     Leverage Advanced Technological Capabilities. Our strengths in advanced
miniaturization, packaging and interconnect technologies enable us to offer
customers advanced design, technology and manufacturing solutions for their
leading-edge products. Our product introduction centers are located in North
America and Europe and provide a high level of engineering expertise to the
customer. Our technological capabilities help our customers to shrink product
size, improve product performance and reduce costs.
 
     There can be no assurance that our strategies, even if successfully
implemented, will reduce the risks of our business. See "Risk Factors."
 
SERVICES
 
     Flextronics offers a broad range of integrated services, providing
customers with a total solution to take a product from initial design through
volume production, test and distribution into post-sales service and support.
 
     Engineering Services. Our product introduction centers coordinate and
integrate our worldwide design, prototype and other engineering capabilities.
Through these product introduction centers, we provide a broad range of
engineering services and, in some cases, dedicated production lines for
prototypes. These services strengthen our relationships with manufacturing
customers and attract new customers requiring advanced engineering services.
 
     To assist customers with initial design, we provide CAE and CAD-based
design, engineering for manufacturability, circuit board layout and test
development. We also coordinate industrial design and tooling for product
manufacturing. After product design, we provide quickturn prototyping. During
this process, we assist with the transition to high volume production. By
participating in product design and prototype development, we can reduce
manufacturing costs and accelerate the time to high volume production.
 
     Materials Procurement and Management. Materials procurement and management
consists of the planning, purchasing, expediting and warehousing of components
and materials. Our inventory management expertise and volume procurement
capabilities contribute to cost reductions and reduce total cycle time. Our
 
                                      S-12
   15
 
industrial parks in China, Hungary and Mexico include providers of many of the
custom components that we use, thus reducing material and transportation costs,
simplifying logistics and facilitating inventory management.
 
     Assembly and Manufacturing. Our assembly and manufacturing operations
include PCB assembly, assembly of subsystems and systems that incorporate PCBs
and complex electromechanical components. A substantial portion of our net sales
are derived from the manufacture and assembly of complete products. Flextronics
employs just-in-time, ship-to-stock and ship-to-line programs, continuous flow
manufacturing, demand flow processes and statistical process control. As OEMs
seek to provide greater functionality in smaller products, they increasingly
require more sophisticated manufacturing technologies and processes. Our
investment in advanced manufacturing equipment and our experience and expertise
in innovative miniaturization, packaging and interconnect technologies (such as
chip scale packaging, chip-on-board and ball grid array) enable us to offer a
variety of advanced manufacturing solutions. In addition, we manufacture
miniature gold-finished PCBs and develop and produce injection-molded plastic
components.
 
     Test. We offer computer-aided testing of assembled PCBs, subsystems and
systems, which contributes significantly to our ability to deliver high-quality
products on a consistent basis. We work with our customers to develop
product-specific test strategies. Our test capabilities include management
defect analysis, in-circuit tests and functional tests. We either custom design
test equipment and software ourselves or use test equipment and software
provided by our customers. In addition, we also provide environmental stress
tests of board or system assemblies.
 
     Distribution. We offer our customers flexible, just-in-time delivery
programs allowing product shipments to be closely coordinated with customers'
inventory requirements. Increasingly, we ship products directly into customers'
distribution channels or directly to the end-user. We believe that this service
can provide our customers with a more comprehensive solution and enable them to
be more responsive to market demands.
 
FACILITIES
 
     Our facilities consist of a global network of industrial parks,
manufacturing and technology centers, regional manufacturing centers and product
introduction centers, providing a total of over 2.7 million square feet of
capacity. Our industrial parks, each incorporating approximately 300,000 square
feet of facilities, are designed for fully integrated, high volume
manufacturing. These industrial parks offer manufacturing and distribution
operations and suppliers that are located together at one site in low cost areas
close to major electronics markets. Manufacturing and technology centers are
facilities that have both medium and high volume manufacturing and product
introduction centers and, as a result, are where we focus on launching
customers' new products and transitioning them to volume production. Each center
features a specific advanced technological competency. Regional manufacturing
facilities range from approximately 50,000 to 165,000 square feet and provide
medium and high volume production in locations close to strategic markets.
Product introduction centers provide a broad range of advanced engineering
services and prototype and low volume production capabilities. All of our
manufacturing facilities are registered to the quality requirements of the
International Organization for Standardization (ISO 9002) or are in the process
of final certification.
 
                                      S-13
   16
 
     The locations of our facilities are as follows:
 
      INDUSTRIAL PARKS
        - Doumen, China
        - Guadalajara, Mexico
        - Sarvar, Hungary
        - Sao Paulo, Brazil (under development)
 
      MANUFACTURING AND TECHNOLOGY CENTERS
        - Althofen, Austria
        - Karlskrona, Sweden
        - San Jose/Fremont, CA, USA
 
      REGIONAL MANUFACTURING FACILITIES
        - Hamilton, Scotland
        - Senai, Malaysia
        - Tab, Hungary
        - Zalaegerzeg, Hungary
 
      PRODUCTION INTRODUCTION CENTERS
        - Althofen, Austria
        - Dallas, TX, USA
        - Karlskrona, Sweden
        - Monza, Italy
        - Niwot, CO, USA
        - San Jose, CA, USA
        - Stockholm, Sweden
        - Westford, MA, USA
 
     Since March 31, 1997, we have increased overall capacity through internal
growth and acquisitions. We enlarged our industrial park in Doumen, China,
constructed (and then expanded) a new industrial park in Guadalajara, Mexico,
and added new facilities in San Jose, California. In addition, our fiscal 1998
acquisitions provided us with a number of new facilities, including an
industrial park in Hungary. As a result of this growth, we grew from
approximately 1.0 million square feet of capacity at the end of fiscal 1997 to
over 2.7 million square feet of capacity at the end of fiscal 1998. We plan to
significantly expand our industrial parks in China, Hungary and Mexico, and we
recently purchased an 88-acre site in Sao Paulo, Brazil, where we plan to
establish a new industrial park.
 
     We may encounter unforeseen difficulties, costs or delays in expanding our
facilities, and this expansion involves a number of risks and uncertainties. See
"Risk Factors -- Risks of Expansion of Operations." In addition, acquisitions
present a number of challenges and risks, including the difficulties of
integrating acquired businesses. See "Risk Factors -- Risks of Acquisitions."
                              SELLING SHAREHOLDERS
 
     The following table sets forth certain information regarding the shares
beneficially owned by the selling shareholders named below as of December 4,
1998, and as adjusted to reflect the sale of the Ordinary Shares being offered
hereby, by each of the Selling Shareholders. Beneficial ownership is determined
in accordance with the rules of the Securities and Exchange Commission that deem
shares to be beneficially owned by any person who has voting or investment power
with respect to such shares. Each of the selling shareholders is an affiliate of
Koninklijke Philips Electronics, N.V., a significant customer of Flextronics.
Percentage ownership is based upon 20,624,411 outstanding Ordinary Shares as of
October 1, 1998.
 


                                                      SHARES BENEFICIALLY                  SHARES BENEFICIALLY
                                                        OWNED PRIOR TO                         OWNED AFTER
                                                           OFFERING          NUMBER OF           OFFERING
                                                      -------------------   SHARES BEING   --------------------
                        NAME                           NUMBER    PERCENT      OFFERED       NUMBER     PERCENT
                        ----                          --------   --------   ------------   --------   ---------
                                                                                       
Osterreichische Philips Industrie GmbH..............  831,125      4.3%       757,000       74,125        *
Philips Beteiligungs GmbH...........................  266,875      1.3        243,000       23,875        *

 
- ---------------
 *  Less than 1%.
 
                                      S-14
   17
 
                                  UNDERWRITER
 
     Subject to the terms and conditions of the underwriting agreement dated
December 7, 1998, NationsBanc Montgomery Securities LLC (the "Underwriter") has
agreed to purchase from Flextronics and the Selling Shareholders an aggregate of
3,700,000 Ordinary Shares at the public offering price less the underwriting
discounts and commissions set forth on the cover page of this Prospectus
Supplement.
 
     The underwriting agreement provides that the obligations of the Underwriter
to purchase the Ordinary Shares offered hereby are subject to certain
conditions. The Underwriter is obligated to purchase all of the Ordinary Shares
offered hereby if any of such shares are purchased.
 
     The Underwriter proposes to offer the Ordinary Shares to the public at the
public offering price set forth on the cover page of this Prospectus Supplement.
After the initial offering, the offering price may be changed by the
Underwriter.
 
     Flextronics has agreed to indemnify the Underwriter against certain
liabilities, including liabilities under the Securities Act.
 
     We have agreed not to offer, sell, contract to sell or otherwise dispose
of, or enter into any transaction which is designed to, or could be expected to,
result in the disposition of any portion of, Ordinary Shares for a period of 90
days after the date of this Prospectus Supplement without the prior written
consent of the Underwriter, except that we may issue, and grant options to
purchase, Ordinary Shares under existing share option and share purchase plans,
and we may issue Ordinary Shares in connection with acquisitions. Such consent
may be given at any time without public notice.
 
     In order to facilitate the offering of the Ordinary Shares, the Underwriter
may engage in transactions that stabilize, maintain or otherwise affect the
market price of the Ordinary Shares. Specifically, the Underwriters may
over-allot Ordinary Shares in connection with this offering, thereby creating a
short position in the Ordinary Shares for their own account. Additionally, to
cover such over-allotments or to stabilize the market price of the Ordinary
Shares, the Underwriter may bid for, and purchase, Ordinary Shares in the open
market. Any of these activities may maintain the market price of our Ordinary
Shares at a level above that which might otherwise prevail in the open market.
The Underwriter is not required to engage in these activities and, if commenced,
may end any of these activities at any time.
 
     In connection with this offering, the Underwriter may engage in passive
market making transactions in the Ordinary Shares on the Nasdaq National Market
immediately prior to the commencement of sales in this offering, in accordance
with Rule 103 of Regulation M. Passive market making consists of displaying bids
on the Nasdaq National Market that are limited by the bid prices of independent
market makers and completing purchases in response to order flow at prices
limited by such bids. Net purchases by a passive market maker on each day are
limited to a specified percentage of the passive market maker's average daily
trading volume in the Ordinary Shares during a specified period and must be
discontinued for any day in which such limit is reached. Passive market making
may stabilize the market price of the Ordinary Shares at a level above that
which might otherwise prevail and, if commenced, may be discontinued at any
time.
 
                                 LEGAL MATTERS
 
     The validity of the Ordinary Shares offered hereby has been passed upon for
us by Allen & Gledhill, Singapore and for the Underwriters by Arfat Selvam &
Gunasingham, Singapore. Certain United States legal matters in connection with
this offering will be passed upon for us by Fenwick & West LLP, Palo Alto,
California, and for the Underwriters by Howard, Rice, Nemerovski, Canady, Falk &
Rabkin, a Professional Corporation, Palo Alto, California.
 
                                      S-15
   18
 
PROSPECTUS
 
                         FLEXTRONICS INTERNATIONAL LTD.
 
                                ORDINARY SHARES
 
     By this prospectus, we may offer up to 5,000,000 Ordinary Shares. We will
provide specific terms for the sale of the Ordinary Shares in supplements to
this prospectus. You should read this prospectus and any prospectus supplement
carefully before you invest.
 
     The Ordinary Shares are quoted on the Nasdaq National Market under the
symbol FLEX. On November 24, 1998 the closing sale price of the Ordinary Shares
was $65.50 per share.
 
                            ------------------------
 
     This investment involves a high degree of risk. See "Risk Factors" in the
supplement to this prospectus.
 
                            ------------------------
 
     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.
 
                            ------------------------
 
This prospectus is dated December 1, 1998
   19
 
                               TABLE OF CONTENTS
 


                                                              PAGE
                                                              ----
                                                           
About this Prospectus.......................................   2
Where You Can Find More Information.........................   2
About Flextronics...........................................   3
Enforcement of Civil Liabilities............................   3
Risk Factors................................................   3
Use of Proceeds.............................................   4
Description of Capital Shares...............................   4
Taxation....................................................   6
Plan of Distribution........................................   8
Legal Matters...............................................   8
Experts.....................................................   8

 
ABOUT THIS PROSPECTUS
 
     This prospectus is part of a registration statement that we filed with the
SEC utilizing a "shelf" registration process. Under this shelf process, we may
sell up to 5,000,000 Ordinary Shares in one or more offerings. This prospectus
provides you with a general description of the Ordinary Shares we may offer.
Each time we sell Ordinary Shares, we will provide a prospectus supplement that
will contain specific information about the terms of that offering. The
prospectus supplement may also add, update or change information contained in
this prospectus. You should read both this prospectus and any prospectus
supplement together with additional information described under the heading
"Where You Can Find More Information."
 
     The registration statement that contains this prospectus (including the
exhibits to the registration statement) contains additional information about
our company and the securities offered under this prospectus. That registration
statement can be read at the SEC web site or at the SEC offices mentioned under
the heading "Where You Can Find More Information." We may only use this
prospectus to sell securities if it is accompanied by a prospectus supplement.
We are only offering these securities in states where the offer is permitted.
 
WHERE YOU CAN FIND MORE INFORMATION
 
     We file annual, quarterly and special reports, proxy statements and other
information with the SEC. You may read and copy any document we file at the
SEC's public reference rooms in Washington, D.C., New York, New York and
Chicago, Illinois. Please call the SEC at 1-800-SEC-0330 for further information
on the public reference rooms. Our SEC filings are also available on the SEC's
Website at "http://www.sec.gov."
 
     We "incorporate by reference" in this prospectus information from other
documents that we file with the SEC, which means that we can disclose important
information to you by referring you to those documents. The information
incorporated by reference is an important part of this prospectus, and
information that we file later with the SEC will automatically update and
supersede this information. We incorporate by reference the documents listed
below, and any future filings we make with the SEC under Sections 13(a), 13(c),
14 or 15(d) of the Securities Exchange Act of 1934 prior to the sale of all the
shares covered by this prospectus:
 
     - Our Annual Report on Form 10-K for the fiscal year ended March 31, 1998;
 
     - Our Quarterly Reports on Form 10-Q for the fiscal quarters ended June 26,
       1998 and September 25, 1998;
 
     - Our Proxy Statement dated August 19, 1998; and
 
     - The description of our Ordinary Shares contained in our Registration
       Statement on Form 8-A dated January 31, 1994.
 
                                        2
   20
 
     You may request a copy of these filings, at no cost, by writing or
telephoning us at:
 
                         FLEXTRONICS INTERNATIONAL LTD.
                               2090 FORTUNE DRIVE
                           SAN JOSE, CALIFORNIA 95131
                        ATTENTION: LAURETTE F. SLAWSON,
                  TREASURER AND DIRECTOR OF INVESTOR RELATIONS
                           TELEPHONE: (408) 428-1300
 
     You should rely only on the information incorporated by reference or
provided in this prospectus or any prospectus supplement (other than any
information superseded by a later prospectus supplement or a later document
filed with the SEC and incorporated by reference into this prospectus). We have
not authorized anyone else to provide you with different information. You should
not assume that the information in this prospectus or any supplement is accurate
as of any date other than the date on the front of those documents.
 
                               ABOUT FLEXTRONICS
 
     Flextronics is a provider of advanced electronics manufacturing services to
original equipment manufacturers ("OEMs") in the telecommunications, networking,
computer, consumer electronics and medical device industries. We offer a full
range of services including product design, printed circuit board ("PCB")
fabrication and assembly, materials procurement, inventory management, final
system assembly and testing, packaging and distribution. The components,
subassemblies and finished products manufactured by us incorporate advanced
interconnect, miniaturization and packaging technologies, such as surface mount,
chip-on-board, ball grid array and miniaturized gold-plated PCB technology. Our
strategy is to use our global manufacturing capabilities and advanced
technological expertise to provide our customers with a complete manufacturing
solution, highly responsive and flexible service, accelerated time to market and
reduced production costs. We target leading OEMs in growing vertical markets
with which we believe we can establish long-term relationships, and serve our
customers on a global basis from our strategically located facilities in North
America, South America, Asia, Western Europe and Central Europe. Our principal
executive offices are located at 514 Chai Chee Lane, #04-13, 1 Bedok Industrial
Estate, Singapore 469029 and our telephone number is 65-449-5255.
 
                        ENFORCEMENT OF CIVIL LIABILITIES
 
     Flextronics is incorporated in Singapore, and certain of its directors and
executive officers reside in Singapore. All or a substantial portion of the
assets of such persons, and a substantial portion of the assets of Flextronics,
are located outside the United States. As a result, it may not be possible for
investors to effect service of process within the United States upon such
persons or Flextronics or to enforce against them, in the United States courts,
judgments obtained in such courts predicated upon the civil liability provisions
of the federal securities laws of the United States. Flextronics has been
advised by its Singapore legal advisors, Allen & Gledhill, that there is doubt
as to the enforceability in Singapore, either in original actions or in actions
for the enforcement of judgments of United States courts, of civil liabilities
predicated upon the federal securities laws of the United States.
 
                                  RISK FACTORS
 
     An investment in the Ordinary Shares involves a high degree of risk. You
should carefully consider the information contained under the heading "Risk
Factors" in the applicable supplement to this prospectus before investing in
Ordinary Shares.
 
                                        3
   21
 
                                USE OF PROCEEDS
 
     Unless otherwise indicated in the applicable supplement to this prospectus,
the net proceeds from the sale of Ordinary Shares offered under this prospectus
will be added to our general funds and may be used to:
 
     - meet our working capital requirements;
 
     - fund capital expenditures;
 
     - repay debt; and
 
     - finance acquisitions of other assets and companies.
 
     Until the net proceeds have been used, they will be invested in short-term
marketable securities.
 
                         DESCRIPTION OF CAPITAL SHARES
 
     The following is a brief summary of the more important rights of holders of
Ordinary Shares under Singapore law and our Articles of Association (the
"Articles"). This summary is not complete. Our Articles and our Memorandum of
Association also are exhibits to the registration statement of which this
prospectus forms a part. The Articles and the Memorandum of Association can be
obtained from our SEC filings as described under the heading "Where You Can Find
More Information" and also at the Company's San Jose, California office and at
the registered office of the Company in Singapore.
 
ORDINARY SHARES
 
     Our authorized capital consists of 100,000,000 Ordinary Shares, par value
S$0.01, of which 20,689,421 shares were outstanding on October 30, 1998. The
Articles enable us in certain circumstances to issue shares with preferential,
deferred or other special rights or restrictions as our directors may determine.
 
     All of our outstanding shares are fully paid and our shareholders are not
subject to any calls on such shares. The shares offered hereby, when issued,
will also be fully paid and investors will not be subject to any calls on such
shares. All of our shares are in registered form, and the shares offered hereby
also will be in registered form. Except in the circumstances permitted by the
Singapore Companies Act, we can neither purchase our outstanding shares nor
grant any financial assistance for the acquisition of our shares.
 
NEW SHARES
 
     New shares may only be issued with the prior approval of our shareholders
in a general meeting. Such approval, if granted, will lapse at the next Annual
General Meeting (or, if earlier, the expiration of the period within which the
next Annual General Meeting is required to be held). At our 1998 Annual General
Meeting, our shareholders provided our directors with general authority to issue
new Ordinary Shares (up to a maximum of 100,000,000 shares) prior to our next
Annual General Meeting. Subject to this, and the provisions of the Singapore
Companies Act and our Articles, our directors may allot and issue new shares on
such terms as they may think fit.
 
SHAREHOLDERS
 
     Only persons who are registered in our books are recognized as shareholders
and absolute owners of the shares. On October 30, 1998, there were approximately
440 holders of Ordinary Shares. We may, on giving not less than 14 days' notice,
close the register of members for any time or times but the register may not be
closed for more than 30 days in any calendar year. Such closure is normally made
for the purpose of determining shareholders' entitlement to receive dividends
and other distributions and would, in the usual case, not exceed 10 days.
 
                                        4
   22
 
TRANSFER OF SHARES
 
     Subject to applicable securities laws, the Ordinary Shares are freely
transferable, and may be transferred by a duly signed instrument of transfer in
a form approved by our directors. The directors may decline to register any
transfer unless, among other things, it has been duly stamped and is presented
for registration together with the share certificate and such other evidence of
title as they may require. We will replace lost or destroyed certificates for
shares upon notice to the Company and upon, among other things, the applicant
furnishing such evidence and indemnity as the directors may require.
 
SHAREHOLDERS' MEETINGS
 
     We are required to hold an Annual General Meeting in each year. Our
directors may convene an Extraordinary General Meeting whenever they think fit
and they must do so upon the request in writing of shareholders representing not
less than one-tenth of the total voting rights of all shareholders. In addition,
two or more shareholders holding not less than one-tenth of our issued share
capital may call a meeting. Unless otherwise required by law or by the Articles,
voting at general meetings is by ordinary resolution (requiring an affirmative
vote of a simple majority of the votes cast at a meeting of which at least 14
days' written notice is given). An ordinary resolution suffices, for example, in
respect of appointments of directors. A special resolution (requiring an
affirmative vote of at least 75% of the votes cast at the meeting of which at
least 21 days' written notice is given) is necessary for certain matters under
Singapore law, such as an alteration of the Articles.
 
VOTING RIGHTS
 
     Voting at any meeting of shareholders is by a show of hands unless a poll
is duly demanded. If voting is by a show of hands, every shareholder who is
present in person or by proxy at the meeting has one vote. On a poll every
shareholder who is present in person or by proxy has one vote for every share
held by him. A poll may be demanded by the chairman of the meeting or by not
less than three members present in person or by proxy and entitled to vote or by
shareholders present in person or by proxy and representing in the aggregate not
less than one-tenth of the total voting rights of all shareholders having the
right to attend and vote at the meeting.
 
     There are no limitations imposed by the laws of Singapore or by the
Articles on the right of nonresident shareholders to hold or vote Ordinary
Shares, other than the limitations described below under "Takeovers" (which are
applicable to all of the Company's shareholders).
 
DIVIDENDS
 
     Since inception, we have not declared or paid any cash dividends and our
current loan agreement prohibits the payment of cash dividends without the
lenders' prior consent. We anticipate that all earnings in the foreseeable
future will be retained to finance our business.
 
BONUS AND RIGHTS ISSUES
 
     We may, with the approval by our shareholders in a general meeting,
capitalize any reserves or profits and distribute them as bonus shares to our
shareholders in proportion to their shareholdings. At our 1998 Annual General
Meeting, our shareholders authorized our directors, at any time on or before
June 30, 1999, to distribute one bonus share for each outstanding Ordinary
Share. Pursuant to such authority, our directors subsequently approved the
distribution of these bonus shares to our shareholders of record on December 10,
1998. Our directors may also issue to shareholders rights to take up additional
shares, in proportion to their shareholdings. Such rights would be subject to
any conditions attached to such issue.
 
TAKEOVERS
 
     The acquisition of our shares is regulated by the Singapore Companies Act
(Chapter 50) and the Singapore Code on Takeovers and Mergers (the "Takeovers
Code"). Any person (or parties acting in concert) acquiring an interest in 25%
or more of the voting rights in the Company is obliged to extend a
 
                                        5
   23
 
takeover offer for the remaining voting shares in accordance with the provisions
of the Takeovers Code. An offer for consideration other than cash must be
accompanied by a cash alternative at not less than the highest price (excluding
stamp duty and commission) paid by the offeror or parties acting in concert with
him for shares of that class within the preceding 12 months. A mandatory
takeover offer is also required to be made if a person holding between 25% and
50% of the voting rights (either on his own or together with parties acting in
concert with him) acquires additional shares representing more than 3% of the
voting rights in any 12-month period.
 
LIQUIDATION OR OTHER RETURN OF CAPITAL
 
     On a winding-up or other return of our capital, subject to any special
rights attaching to any other class of shares, holders of Ordinary Shares will
be entitled to participate in any surplus assets in proportion to their
shareholdings.
 
INDEMNITY
 
     As permitted by the laws of Singapore, the Articles provide that, subject
to the Singapore Companies Act, our directors and officers will be indemnified
by us against any liability incurred by them in defending any proceedings,
whether civil or criminal, which relate to anything done or omitted to have been
done as an officer, director or employee of the Company and in which judgment is
given in their favor or in which they are acquitted or in connection with any
application under any statute for relief from liability in respect thereof in
which relief is granted by the court. Directors and officers may not be
indemnified by us against any liability to the Company for negligence, default,
breach of duty or breach of trust.
 
TRANSFER AGENT
 
     Our transfer agent is Boston EquiServe, P.O. Box 8040, Boston,
Massachusetts 02266-8040.
 
                                    TAXATION
 
     This summary of Singapore and U.S. tax considerations is based on current
law and is provided for general information. The discussion does not purport to
deal with all aspects of taxation that may be relevant to particular
shareholders in light of their investment or tax circumstances, or to certain
types of shareholders (including insurance companies, tax-exempt organizations,
regulated investment companies, financial institutions or broker-dealers, and
shareholders that are not U.S. Shareholders (as defined below)) subject to
special treatment under the U.S. federal income tax laws. Such shareholders
should consult their own tax advisors regarding the particular tax consequences
to such shareholders of any investment in the Ordinary Shares.
 
INCOME TAXATION UNDER SINGAPORE LAW
 
     Under current provisions of the Income Tax Act, Chapter 134 of Singapore,
corporate profits are taxed at a rate equal to 26.0%. Under Singapore's taxation
system, the tax paid by a company is deemed paid by its shareholders. Thus, the
shareholders receive dividends net of the tax paid by the Company. Dividends
received by either a resident or a nonresident of Singapore are not subject to
withholding tax. Shareholders are taxed on the gross amount of dividends (i.e.,
the cash amount of the dividend plus the amount of corporate tax paid by the
Company). The tax paid by the Company will be available to shareholders as a tax
credit to offset the Singapore income tax liability on their overall income
(including the gross amount of dividends). No tax treaty currently exists
between the Republic of Singapore and the U.S.
 
     Under current Singapore tax law there is no tax on capital gains, and,
thus, any profits from the disposal of shares are not taxable in Singapore
unless the vendor is regarded as carrying on a trade in shares in Singapore (in
which case, the disposal profits would be taxable as trade profits rather than
capital gains).
 
     There is no stamp duty payable in respect of the holding and disposition of
shares, or the acquisition of newly issued shares. When outstanding shares are
acquired in Singapore, stamp duty is payable on the instrument of transfer of
the shares at the rate of S$2 for every S$1,000 of the market value of the
shares. The
                                        6
   24
 
stamp duty is borne by the purchaser unless there is an agreement to the
contrary. Where the instrument of transfer is executed outside of Singapore,
stamp duty must be paid if the instrument of transfer is received in Singapore.
Under the Company's Articles of Association, its directors are authorized to
refuse to register a transfer unless the instrument of transfer has been duly
stamped.
 
INCOME TAXATION UNDER UNITED STATES LAW
 
     Individual shareholders that are U.S. citizens or resident aliens (as
defined in the Internal Revenue Code), corporations or partnerships or other
entities created or organized under the laws of the United States, or any
political subdivision thereof, and certain trusts and estates ("U.S.
Shareholders") will, upon the sale or exchange of a share, recognize gain or
loss for U.S. income tax purposes in an amount equal to the difference between
the amount realized and the U.S. Shareholder's tax basis in such a share. If
paid in currency other than U.S. dollars, the U.S. dollar amount realized (as
determined on the trade date) is determined by translating the foreign currency
into U.S. dollars at the spot rate in effect on the settlement date of the sale
in the case of a U.S. Shareholder that is a cash basis taxpayer. An accrual
basis taxpayer may elect to use the spot rate in effect on the settlement date
of the sale by filing a statement with the U.S. Shareholder's first return in
which the election is effective clearly indicating that the election has been
made. Such an election must be applied consistently from year to year and cannot
be changed without the consent of the Internal Revenue Service. Such gain or
loss will be capital gain or loss if the share was a capital asset in the hands
of the U.S. Shareholder and will not be short-term capital gain or loss if the
share has been held for more than one year. If a U.S. Shareholder receives any
currency other than U.S. dollars on the sale of a share, such U.S. Shareholder
may recognize ordinary income or loss as a result of currency fluctuations
between the date of such sale and the date such sale proceeds are converted into
U.S. dollars.
 
     U.S. Shareholders will be required to report as income for U.S. income tax
purposes the amount of any dividend received from the Company to the extent paid
out of the current or accumulated earnings and profits of the Company, as
determined under current U.S. income tax principles. If over 50.0% of the
Company's stock (by vote or value) were owned by U.S. Shareholders who
individually held 10.0% or more of the Company's voting stock, such U.S.
Shareholders potentially would be required to include in income a portion or all
of their pro rata share of the Company's and its non-U.S. subsidiaries' earnings
and profits. If 50.0% or more of the Company's assets during a taxable year
produced or were held for the production of passive income, as defined in
section 1297(b) of the Internal Revenue Code (e.g., certain forms of dividends,
interest and royalties), or 75.0% or more of the Company's gross income for a
taxable year was passive income, adverse U.S. tax consequences could result to
U.S. shareholders of the Company.
 
     Shareholders that are not U.S. Shareholders ("non-U.S. shareholders") will
not be required to report for U.S. federal income tax purposes the amount of any
dividend received from the Company. Non-U.S. shareholders, upon the sale or
exchange of a share, would generally not be required to recognize gain or loss
for U.S. federal income tax purposes.
 
ESTATE TAXATION
 
     In the case of an individual who is not domiciled in Singapore, a Singapore
estate tax is imposed on the value of all movable and immovable properties
situated in Singapore. The shares of the Company are considered to be situated
in Singapore. Thus, an individual shareholder who is not domiciled in Singapore
at the time of his or her death will be subject to Singapore estate tax on the
value of any such shares held by the individual upon the individual's death.
Such a shareholder will be required to pay Singapore estate tax to the extent
that the value of the shares (or in aggregate with any other assets subject to
Singapore estate tax) exceeds S$600,000. Any such excess will be taxed at a rate
equal to 5.0% on the first S$12,000,000 of the individual's Singapore chargeable
assets and thereafter at a rate equal to 10.0%. An individual shareholder who is
a U.S. citizen or resident (for U.S. estate tax purposes) also will have the
value of the shares included in the individual's gross estate for U.S. estate
tax purposes. An individual shareholder generally will be entitled to a tax
credit against the shareholder's U.S. estate tax to the extent the individual
shareholder actually pays Singapore estate tax on the value of the shares;
however, such tax credit is generally limited to the percentage of the U.S.
estate tax attributable to the inclusion of the value of the shares included in
the shareholder's gross
                                        7
   25
 
estate for U.S. estate tax purposes, adjusted further by a pro rata
apportionment of available exemptions. Individuals who are domiciled in
Singapore should consult their own tax advisors regarding the Singapore estate
tax consequences of their investment.
 
                              PLAN OF DISTRIBUTION
 
     We may sell the Ordinary Shares (a) through agents; (b) to or through one
or more underwriters; or (c) directly to investors. Any underwriters or agents
will be identified and their compensation described in a prospectus supplement.
 
     We (directly or through agents) may sell, and the underwriters may resell,
the Ordinary Shares in one or more transactions, including negotiated
transactions, at a fixed public offering price or prices, which may be changed,
or at market prices prevailing at the time of sale, at prices related to such
prevailing market prices or at negotiated prices.
 
     In connection with the sale of Ordinary Shares, underwriters or agents may
receive compensation from us or from purchasers of the Ordinary Shares for whom
they may act as agents. The underwriters may sell Ordinary Shares to or through
dealers, who may also receive compensation from purchasers of the Ordinary
Shares for whom they act as agents. Compensation may be in the form of
discounts, concessions or commissions. Underwriters, dealers and agents that
participate in the distribution of the Ordinary Shares may be underwriters as
defined in the Securities Act of 1933, and any discounts or commissions received
by them from us and any profit on the resale of the Ordinary Shares by them may
be treated as underwriting discounts and commissions under the Securities Act.
The applicable prospectus supplement may describe other terms of the offering,
including any discounts or concessions allowed or reallowed or paid to dealers.
 
     We may grant any underwriters who participate in the distribution of
Ordinary Shares an option to purchase additional Ordinary Shares to cover any
over-allotments.
 
     We may have agreements with the underwriters, dealers and agents to
indemnify them against certain civil liabilities, including liabilities under
the Securities Act, or to contribute with respect to payments which the
underwriters, dealers or agents may be required to make as a result of those
certain civil liabilities.
 
     Underwriters, dealers and agents may engage in transactions with, or
perform services for, us or our subsidiaries in the ordinary course of their
businesses.
 
                                 LEGAL MATTERS
 
     The validity of the Ordinary Shares offered hereby has been passed upon for
the Company by Allen & Gledhill, Singapore. Certain legal matters relating to
the Ordinary Shares offered hereby will be passed upon for any underwriters by
the counsel for such underwriters named in the applicable prospectus supplement.
 
                                    EXPERTS
 
     Our consolidated financial statements appearing in our Annual Report (Form
10-K) for the year ended March 31, 1998 have been audited by Arthur Andersen
LLP, independent public accountants as indicated in their report therein. Such
consolidated financial statements are incorporated herein by reference in
reliance upon such report given upon the authority of such firm as experts in
accounting and auditing. Future financial statements of the Company and the
reports thereon of Arthur Andersen LLP also will be incorporated by reference in
this prospectus in reliance upon the authority of that firm as experts in giving
those reports to the extent said firm has audited those financial statements and
consented to the use of their reports thereon.
 
                                        8
   26
 
PROSPECTUS
 
                         FLEXTRONICS INTERNATIONAL LTD.
                        UP TO 3,262,403 ORDINARY SHARES
                            ------------------------
 
     The 3,262,403 shares covered by this prospectus were previously issued by
Flextronics in its acquisitions of Neutronics Electronic Industries Holding AG,
DTM Products, Inc., Alatron, Inc., Marathon Business Park LLC, Energipilot AB
and Conexao Informatica Ltda. These shares may be offered and sold over time by
the shareholders named in this Prospectus under the heading "Selling
Shareholders," by their pledges or donees, or by other transferees that receive
such Shares in transfers other than public sales.
 
     The selling shareholders may sell their Flextronics shares in the open
market at prevailing market prices, or in private transactions at negotiated
prices. They may sell the shares directly, or may sell them through
underwriters, brokers or dealers. Underwriters, brokers, or dealers may receive
discounts, concessions or commissions from the selling shareholders or from the
purchaser, and this compensation might be in excess of the compensation
customary in the type of transaction involved. See "Plan of Distribution."
 
     We will not receive any of the proceeds from the sale of these shares.
 
     The Ordinary Shares are quoted on the Nasdaq National Market under the
symbol FLEX. On October 26, 1998 the closing sale price of the Ordinary Shares
was $44.75 per share.
 
                            ------------------------
 
     This investment involves a high degree of risk. See "Risk Factors"
beginning on page A-4.
                            ------------------------
 
     Neither the Securities and Exchange Commission nor any state securities
commission has appoved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.
 
                THE DATE OF THIS PROSPECTUS IS OCTOBER 30, 1998
   27
 
                      WHERE YOU CAN FIND MORE INFORMATION
 
     We file annual, quarterly and special reports, proxy statements and other
information with the SEC. You may read and copy any document we file at the
SEC's public reference rooms in Washington, D.C., New York, New York and
Chicago, Illinois. Please call the SEC at 1-800-SEC-0330 for further information
on the public reference rooms. Our SEC filings are also available on the SEC's
Website at "http://www.sec.gov."
 
     The SEC allows us to "incorporate by reference" information from other
documents that we file with them, which means that we can disclose important
information by referring to those documents The information incorporated by
reference is considered to be part of this prospectus, and information that we
file later with the SEC will automatically update and supersede this
information. We incorporate by reference the documents listed below, and any
future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of
the Securities Exchange Act of 1934 prior to the sale of all the shares covered
by this Prospectus:
 
     - Our Annual Report on Form 10-K for the fiscal year ended March 31, 1998;
 
     - Our Quarterly Report on Form 10-Q for the quarter ended June 26, 1998;
 
     - Our Proxy Statement dated August 19, 1998; and
 
     - The description of our Ordinary Shares contained in its Registration
       Statement on Form 8-A dated January 31, 1994.
 
     You may request a copy of these filings, at no cost, by writing or
telephoning us at:
 
       Flextronics International Ltd.
        2090 Fortune Drive
        San Jose, California 95131
        Attention: Laurette F. Slawson,
        Treasurer and Director of Investor Relations
        Telephone: (408) 428-1300
 
     You should rely only on the information incorporated by reference or
provided in this prospectus or any supplement (other than any information
superseded by a later document filed with the SEC and incorporated by reference
in this Prospectus). We have not authorized anyone else to provide you with
different information. The selling shareholders may not make an offer of these
shares in any state where the offer is not permitted. You should not assume that
the information in this prospectus or any supplement is accurate as of any date
other than the date on the front of those documents
 
                               TABLE OF CONTENTS
 


                                                              PAGE
                                                              ----
                                                           
Where you can find more information.........................   A-2
The Company.................................................   A-3
Enforcement of Civil Liabilities............................   A-3
Risk Factors................................................   A-4
Selling Shareholders........................................   A-8
Plan of Distribution........................................   A-9
Legal Matters...............................................   A-9

 
                                       A-2
   28
 
                                  THE COMPANY
 
     Flextronics International Ltd. (the "Company" or Flextronics) is a provider
of advanced electronics manufacturing services to original equipment
manufacturers ("OEMs") in the telecommunications, networking, computer, consumer
electronics and medical device industries. Flextronics offers a full range of
services including product design, printed circuit board ("PCB") fabrication and
assembly, materials procurement, inventory management, final system assembly and
testing, packaging and distribution. The components, subassemblies and finished
products manufactured by Flextronics incorporate advanced interconnect,
miniaturization and packaging technologies, such as surface mount ("SMT"),
chip-on-board ("COB"), ball grid array ("BGA") and miniaturized gold-plated PCB
technology. The Company's strategy is to use its global manufacturing
capabilities and advanced technological expertise to provide its customers with
a complete manufacturing solution, highly responsive and flexible service,
accelerated time to market and reduced production costs. The Company targets
leading OEMs in growing vertical markets with which it believes it can establish
long-term relationships, and serves its customers on a global basis from its
strategically located facilities in North America, South America, Asia, Western
Europe and Central Europe. The Company's principal executive offices are located
at 514 Chai Chee Lane, #04-13, 1 Bedok Industrial Estate, Singapore 469029 and
its telephone number is 65-449-5255.
 
                        ENFORCEMENT OF CIVIL LIABILITIES
 
     The Company is incorporated in Singapore under the Companies Act. Certain
of its directors and executive officers (and certain experts named in this
Prospectus) reside in Singapore. All or a substantial portion of the assets of
such persons, and a substantial portion of the assets of the Company (other than
its U.S. subsidiaries), are located outside the United States. As a result, it
may not be possible for persons purchasing Ordinary Shares to effect service of
process within the United States upon such persons or the Company or to enforce
against them, in the United States courts, judgments obtained in such courts
predicated upon the civil liability provisions of the federal securities laws of
the United States. The Company has been advised by its Singapore legal advisors,
Allen & Gledhill, that there is doubt as to the enforceability in Singapore,
either in original actions or in actions for the enforcement of judgments of
United States courts, of civil liabilities predicated upon the federal
securities laws of the United States.
 
                                       A-3
   29
 
                                  RISK FACTORS
 
     You should carefully consider the following factors as well as the other
information contained or incorporated by reference in this prospectus before
deciding to invest in the Ordinary Shares of Flextronics. These factors could
cause our future results to differ materially from those expressed or implied in
forward-looking statements made by us.
 
RISKS OF EXPANSION OF OPERATIONS
 
     We have grown rapidly in recent periods, and this growth may not continue.
A significant amount of our past growth was due to our completion of a number of
acquisitions. We have reduced our focus on growth through acquisitions, and have
not completed any acquisitions in fiscal 1999. As a result, our future growth
will depend on internal expansion to a greater extent than has our past growth.
Internal growth will require us to:
 
     - develop new customer relationships and expand existing ones,
 
     - improve our operational and information systems, and
 
     - further expand our manufacturing capacity.
 
     We plan to further expand our manufacturing capacity by expanding our
facilities and by adding new equipment. This will require substantial new
capital expenditures and operating lease commitments. Funds may not be available
for this expansion, and we may not be able to obtain loans or operating leases
on attractive terms. The expansion of our manufacturing facilities involves
significant risks, including cost overruns, construction delays, equipment
delays or shortages, labor shortages and disputes and production start-up
problems. Delays in the expansion of our facilities could adversely affect our
growth and our ability to meet customers' delivery schedules.
 
     We may experience inefficiencies as we integrate new operations, expand
existing ones and manage geographically dispersed operations. We may not succeed
in managing expansion effectively, and a failure to do so could have a material
adverse effect on us.
 
     In addition, we expect our expansion to result in new fixed and operating
expenses, including substantial increases in depreciation expense and rental
expense, that will increase our cost of sales. If our sales levels do not
increase sufficiently to offset these expenses, our operating results would be
adversely affected. Our expansion, both through acquisitions and internal
growth, has contributed to our incurring significant accounting charges and
experiencing volatility in our operating results. We may continue to experience
volatility in operating results in connection with future expansion efforts.
 
RISKS OF ACQUISITIONS
 
     Our acquisitions during the last two fiscal years represented a significant
expansion of our operations. Acquisitions involve a number of risks and
challenges, including:
 
     - diversion of management's attention;
 
     - the need to integrate acquired operations; and
 
     - potential loss of key employees and customers of the acquired companies.
 
     In order to integrate acquired operations, we must implement our management
information systems and our operating systems, and assimilate and manage the
personnel of the acquired operations. The difficulties of this integration may
be further complicated by geographic distances. The integration of acquired
businesses may not be successful, and could result in disruption in other parts
of our business. In the event we are unsuccessful in integrating acquired
operations, we would be materially adversely affected.
 
     We may not have had any experience operating in the geographic market of
the acquired business. For example, prior to the acquisitions of the Karlskrona
facilities, Neutronics and Conexao, we had no experience operating in Sweden,
Central Europe or Brazil. In addition, acquisitions increase our expenses and
working capital requirements. As a result of these and other factors, we may not
achieve anticipated levels of
                                       A-4
   30
 
profitability at acquired operations or realize other anticipated benefits of an
acquisition. Furthermore, any future acquisitions may require debt or equity
financing, which could increase our leverage or be dilutive to our existing
shareholders. No assurance can be given that we will consummate any acquisitions
in the future.
 
VARIABILITY OF CUSTOMER REQUIREMENTS AND OPERATING RESULTS
 
     Electronics manufacturing service providers must provide increasingly rapid
product turnaround for their customers. We generally do not obtain firm
long-term purchase commitments from our customers, and over the past few years
we have experienced reduced lead-times in customer orders. Customers may cancel
their orders, change production quantities or delay production for a number of
reasons. Cancellations, reductions or delays by a significant customer or by a
group of customers would adversely affect our results of operations.
 
     In addition to the variability resulting from the short-term nature of our
customers' commitments, other factors may contribute to significant fluctuations
in our results of operations. These factors include:
 
     - the timing of customer orders;
 
     - the volume of these orders relative to our capacity;
 
     - customers' introductions and market acceptance of new products;
 
     - changes in demand for customers' products;
 
     - the timing of our expenditures in anticipation of future orders;
 
     - our effectiveness in managing manufacturing processes;
 
     - changes in cost and availability of labor and components;
 
     - changes in our product mix;
 
     - changes in economic conditions;
 
     - local factors and events that may affect our production volume (such as
       local holidays); and
 
     - seasonality in customers' product requirements.
 
     We make significant decisions, including the levels of business that we
will seek and accept, production schedules, component procurement commitments,
personnel needs and other resource requirements, based on our estimates of
customer requirements. Our ability to estimate future customer requirements is
reduced by the short-term nature of our customers' commitments and the
possibility of rapid changes in demand for their products. On occasion,
customers may require rapid increases in production, which can stress our
resources and reduce margins. Although we have increased our manufacturing
capacity, and plan further increases, there can be no assurance that we will
have sufficient capacity at any given time to meet our customers' demands. In
addition, as many of our costs and operating expenses are relatively fixed, a
reduction in customer demand can have material adverse effect on our gross
margins and operating income.
 
CUSTOMER CONCENTRATION; DEPENDENCE ON ELECTRONICS INDUSTRY
 
     Sale to our five largest customers had represented a majority of our net
sales in recent periods. The identity of our principal customers has varied from
year to year, and our principal customers may not continue to purchase services
from us at current levels, if at all. Significant reductions in sales to any of
these customers, or the loss of major customers, would have a material adverse
effect on us. We cannot assure the timely replacement of expired, canceled, or
reduced contracts with new business. See "-- Variability of Customer
Requirements and Operating Results."
 
     Factors affecting the electronics industry in general could have a material
adverse effect on our customers, and as a result on us. Our customers' markets
are characterized by rapidly changing technology and evolving industry
standards. This frequently results in short product life cycles. Our success
will depend to a significant extent on the success achieved by our customers in
developing and marketing their products, some of which are new and untested. If
customers' products become obsolete or fail to gain widespread
                                       A-5
   31
 
commercial acceptance, our business may be materially adversely affected. Our
customer's markets are also subject to economic cycles and are likely in the
future to experience recessionary periods in the future. A recession in the
industries we serve could have a material adverse effect on us.
 
REPLACEMENT OF MANAGEMENT INFORMATION SYSTEMS; YEAR 2000 COMPLIANCE
 
     We are in the process of replacing our management information system with a
new enterprise management information system that is designed to provide
enhanced functionality. The new system will significantly affect many aspects of
our business, including our manufacturing, sales and marketing and accounting
functions. In addition, the successful implementation of this system will be
important to our future growth. We currently anticipate that the installation of
the new system will be completed in the second quarter of fiscal 1999, but it
could be delayed until later. Implementation of the new system could cause
significant disruption in operations. Difficulties or delays in the
implementation of the new system could adversely affect our ability to meet
customers' production schedules and our ability to access timely financial and
operating information.
 
     We have been advised that our new enterprise management information system
is Year 2000 compliant. However, there can be no assurance that the new system
will be Year 2000 compliant or that it will be implemented by January 1, 2000.
If the new system is not Year 2000 compliant or is not implemented by Year 2000
we could be materially adversely effected. In addition, we could be adversely
affected if our customers and suppliers do not have information systems that are
Year 2000 compliant.
 
RISK OF INCREASED TAXES
 
     We have structured our operations in a manner designed to maximize income
in countries where tax incentives have been extended to encourage foreign
investment or where income tax rates are low. Our taxes could increase if these
tax incentives are not renewed upon expiration, or tax rates applicable to us
are increased.
 
     Substantially all of the products manufactured by our Asian subsidiaries
are sold to customers based in North America and Europe. We believe that profits
from our Asian operations are not sufficiently connected to jurisdictions in
North America or Europe to give rise to income taxation there. However, tax
authorities in jurisdictions in North America and Europe could challenge the
manner in which profits are allocated among our subsidiaries, and we may not
prevail in any such challenge. If our Asian profits became subject to income
taxes in such other jurisdictions, our worldwide effective tax rate could
increase.
 
SIGNIFICANT LEVERAGE
 
     Our level of indebtedness presents risks to investors, including the
possibility that we may be unable to generate cash sufficient to pay the
principal of and interest on the indebtedness when due. Additionally, our
leverage may make us more vulnerable to economic downturns, may limit our
ability to pursue new business opportunities and may reduce our flexibility in
responding to changing business and economic conditions.
 
RISKS OF COMPETITION
 
     The electronics contract manufacturing industry is extremely competitive
and includes hundreds of companies, several of whom have achieved substantial
market share. Current and prospective customers also evaluate our capabilities
against the merits of internal production. Certain of our competitors, including
Solectron Corporation and SCI Systems, have substantially greater market shares
than us, and substantially greater manufacturing, financial, research and
development and marketing resources. In recent years many participants in the
industry, including us, have substantially expanded their manufacturing
capacity. If overall demand for contract manufacturing services should decrease,
this increased capacity could result in substantial pricing pressures, which
could adversely affect our operating results.
 
                                       A-6
   32
 
RISKS OF INTERNATIONAL OPERATIONS
 
     The geographical distances between Asia, the United States, Mexico and
Europe create a number of logistical and communications challenges. Our
manufacturing operations are located in a number of countries including Austria,
Brazil, China, Hungary, Malaysia, Mexico, Sweden, the United Kingdom and the
United States. As a result, we are affected by economic and political conditions
in those countries, including:
 
     - fluctuations in the value of currency;
 
     - changes in labor conditions;
 
     - longer payment cycles;
 
     - greater difficulty in collecting accounts receivable;
 
     - burdens and costs of compliance with a variety of foreign laws; and
 
     - in some countries, political instability.
 
     Increases in duties and taxation, the imposition of restrictions on
currency conversion or the transfer of funds, limitations on imports or exports
or the expropriation of private enterprises could also have a material adverse
effect on us. We could also be adversely affected if the current policies
encouraging foreign investment or foreign trade by our host countries were to be
reversed. In addition, the attractiveness of our services to our U.S. customers
can be affected by changes in U.S. trade policies, such as "most favored nation"
status and trade preferences for certain Asian nations. For example, trade
preferences extended by the United States to Malaysia in recent years were not
renewed in 1997. Finally, we could be adversely affected by inadequate
infrastructure or the lack of adequate power and water supplies, transportation,
raw materials and parts in countries in which we operate.
 
CURRENCY FLUCTUATIONS
 
     With the acquisitions of the Karlskrona facilities, Neutronics and Conexao,
a significant portion of our business is conducted in the Swedish kronor,
Austrian schilling and Brazilian real. In addition, some of our costs, such as
payroll and rent, are denominated in currencies such as the Singapore dollar,
the Hong Kong dollar, the Malaysian ringgit, the Hungarian forint and the
Mexican peso, as well as the kronor, the schilling and the real. In recent
years, the Hungarian forint, Brazilian real and Mexican peso have experienced
significant devaluations. Changes in exchange rate between these and other
currencies and the U.S. dollar will affect our cost of sales and operating
margins. The impact of future exchange rate fluctuations cannot be predicted.
 
     Our European and Asian operations use financial instruments, primarily
forward purchase contracts, to hedge certain fixed Japanese yen, German
deutschmark, U.S. dollar, and other foreign currency commitments arising from
trade accounts payable and fixed purchase obligations. Because we hedge only
fixed obligations, we do not expect that these hedging activities will have a
material effect on our results of operations or cash flows. However, our hedging
activities may be unsuccessful, and we may change or reduce our hedging
activities in the future.
 
                                       A-7
   33
 
                              SELLING SHAREHOLDERS
 
     The following table sets forth certain information regarding the shares
beneficially owned by the selling shareholders named below as of September 1,
1998, the shares that may be offered and sold from time to time by such selling
shareholders pursuant to this Prospectus (assuming each selling shareholder
sells all of the Ordinary Shares offered hereby) and the nature of any position,
office or other material relationship which each such selling shareholder has
had with the Company. The selling shareholders named below, together with any
pledgee or donee of any such named shareholders, and any person who may purchase
shares offered hereby from any such named shareholders in a private transaction
in which they are assigned such shareholders' rights to registration of their
shares, are referred to in this Prospectus as the "Selling Shareholders." Except
as indicated below, the shares that may be offered and sold pursuant to this
Prospectus represent all of the shares beneficially owned by each named selling
shareholder as of September 1, 1998. All of such shares were acquired by the
selling shareholders in connection with the Company's acquisitions of
Neutronics, Energipilot, DTM, Conexao and Altatron. Because the Selling
Shareholders may offer from time to time all or some of their shares under this
Prospectus, no assurances can be given as to the actual number of shares that
will be sold by any Selling Shareholder or that will be held by the Selling
Shareholder after completion of such sales.
 


                                                         SHARES BENEFICIALLY      MAXIMUM
                                                              OWNED(1)           NUMBER OF
                                                        ---------------------    SHARES TO
             NAME OF SELLING SHAREHOLDER                NUMBER     PERCENT(2)    BE OFFERED
             ---------------------------                -------    ----------    ----------
                                                                        
Bo Sjunnesson(3)......................................   30,000         *          30,000
Osterreichische Philips Industrie GmbH(4).............  831,125       4.0%        831,125
Philips Beteiligungs GmbH(4)..........................  266,875       1.3%        266,875
Hui Shing Leong(5)....................................  930,480       4.5%        922,980
Walter Mayrhofer(6)...................................   51,000         *          51,000
Robert J. Grubb(7)....................................  165,245         *         165,245
Nicole Leann Grubb Trust..............................    3,930         *           3,930
Kristen Lee Grubb Trust...............................    3,930         *           3,930
Kenneth Garrett Grubb Trust...........................    2,620         *           2,620
Capone Investments, Inc...............................   16,830         *          16,830
Plum Street Investments, Ltd..........................   33,660         *          33,660
Celso Moraes Camargo Filho(8).........................  303,288         *         303,288
3C Comercio E Participacoes(9)........................  303,288         *         303,288
Joseph L. Jeng(10)....................................  630,920         *         630,920
Marrina C. Jeng(11)...................................  630,920         *         630,920

 
- ---------------
  *  Less than 1%.
 
 (1) Beneficial ownership is determined in accordance with the rules of the
     Securities and Exchange Commission that deem shares to be beneficially
     owned by any person who has voting or investment power with respect to such
     shares. Ordinary Shares subject to options that are currently exercisable
     or exercisable within 60 days after September 1, 1998 are deemed to be
     outstanding and to be beneficially owned by the person holding such options
     for the purpose of computing the percentage ownership of such person but
     are not treated as outstanding for the purpose of computing the percentage
     ownership of any other person.
 
 (2) Percentage ownership is based upon 20,624,411 outstanding Ordinary Shares
     as of October 1, 1998.
 
 (3) Mr. Bo Sjunnesson is an officer of a subsidiary of the Company, and was a
     director, officer and the sole shareholder of Energipilot prior to its
     acquisition by the Company.
 
 (4) Osterreichische Philips Industrie GmbH and Philips Beteiligungs GmbH were
     shareholders of Neutronics until its acquisition by the Company, and are
     affiliates of Philips Electronics, a significant customer of the Company.
 
 (5) Mr. Hui Shing Leong is a director of the Company, and was a director and
     shareholder of Neutronics until its acquisition by the Company. Shares
     beneficially owned by Mr. Hui include 7,500 shares subject to options
     exercisable within 60 days after October 1, 1998 held by Mr. Hui.
 
 (6) Mr. Walter Mayrhofer is an officer of a subsidiary of the Company and was a
     director, officer and shareholder of Neutronics until its acquisition by
     the Company.
 
 (7) Mr. Robert J. Grubb is an officer of a subsidiary of the Company, and was
     an officer, director and shareholder of DTM until its acquisition by the
     Company.
 
                                       A-8
   34
 
 (8) Mr. Celso Moraes Camargo Filho is an officer of a subsidiary of the Company
     and was an officer, director and member of Conexao until its acquisition by
     the Company. Shares beneficially owned by Mr. Celso Moraes Camargo Filho
     include 31 shares held by 3C Comercio E Participacoes Ltda. See Note 9.
 
 (9) Shares beneficially owned by 3C Comercio E Participacoes Ltda. include
     303,257 shares held by Mr. Celso Moraes Camargo Filho, who controls 3C
     Comercio E Participacoes Ltda. See Note 8.
 
(10) Shares beneficially owned by Mr. Joseph L. Jeng include 315,460 shares held
     by Mrs. Marrina C. Jeng. See Note 11. Mr. Jeng was an officer and director
     of Altatron until its acquisition by the Company.
 
(11) Shares beneficially owned by Mrs. Marrina C. Jeng include 315,460 shares
     held by Mr. Joseph L. Jeng. See Note 10. Ms. Jeng was an officer and
     director of Altatron until its acquisition by the Company.
 
                              PLAN OF DISTRIBUTION
 
     The Selling Shareholders may sell or distribute some or all of the Shares
from time to time through underwriters or dealers or brokers or other agents or
directly to one or more purchasers, including pledgees, in transactions (which
may involve crosses and block transactions) on Nasdaq, in privately negotiated
transactions (including sales pursuant to pledges) or in the over-the-counter
market, or in a combination of such transactions. Such transactions may be
effected by the Selling Shareholders at market prices prevailing at the time of
sale, at prices related to such prevailing market prices, at negotiated prices,
or at fixed prices, which may be changed. Brokers, dealers, agents or
underwriters participating in such transactions as agent may receive
compensation in the form of discounts, concessions or commissions from the
Selling Shareholders (and, if they act as agent for the purchaser of such
shares, from such purchaser). Such discounts, concessions or commissions as to a
particular broker, dealer, agent or underwriter might be in excess of those
customary in the type of transaction involved. This Prospectus also may be used,
with the Company's consent, by donees or pledgees of the Selling Shareholders,
or by other persons acquiring Shares and who wish to offer and sell such Shares
under circumstances requiring or making desirable its use.
 
     The Selling Shareholders and any such underwriters, brokers, dealers or
agents that participate in such distribution may be deemed to be "underwriters"
within the meaning of the Securities Act, and any discounts, commissions or
concessions received by any such underwriters, brokers, dealers or agents might
be deemed to be underwriting discounts and commissions under the Securities Act.
Neither the Company nor the Selling Shareholders can presently estimate the
amount of such compensation.
 
     The Company will pay substantially all of the expenses incident to this
Offering of the Shares by the Selling Shareholders to the public other than
commissions and discounts of underwriters, brokers, dealers or agents. The
Company has agreed to indemnify the Selling Shareholders against certain
liabilities, including liabilities arising under the Securities Act, in
connection with the offer and sale of the Shares, and Selling Shareholders may
indemnify brokers, dealers, agents or underwriters that participate in
transactions involving sales of the Shares against certain liabilities,
including liabilities arising under the Securities Act.
 
     In order to comply with certain states' securities laws, if applicable, the
Shares will be sold in such jurisdictions only through registered or licensed
brokers or dealers. In addition, in certain states the Shares may not be sold
unless the Shares have been registered or qualified for sale in such state or an
exemption from registration or qualification is available and is complied with.
 
     The Shares were originally issued to former shareholders of Neutronics,
DTM, Energipilot, Conexao and Altatron in connection with the acquisitions of
such companies pursuant to exemptions from the registration requirements of the
Securities Act provided by Section 4(2) thereof.
 
                                 LEGAL MATTERS
 
     The validity of the securities offered hereby has been passed upon for the
Company by Allen & Gledhill, Singapore.
 
                                       A-9
   35
 
- ------------------------------------------------------
- ------------------------------------------------------
 
     YOU MAY RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS
SUPPLEMENT AND THE ACCOMPANYING PROSPECTUSES. WE HAVE NOT AUTHORIZED ANYONE TO
PROVIDE INFORMATION DIFFERENT FROM THAT CONTAINED IN THIS PROSPECTUS SUPPLEMENT
AND THE ACCOMPANYING PROSPECTUSES. NEITHER THE DELIVERY OF THIS PROSPECTUS
SUPPLEMENT OR THE ACCOMPANYING PROSPECTUSES NOR THE SALE OF ORDINARY SHARES
MEANS THAT INFORMATION CONTAINED IN THIS PROSPECTUS SUPPLEMENT OR THE
ACCOMPANYING PROSPECTUSES IS CORRECT AFTER THE DATE OF THIS PROSPECTUS
SUPPLEMENT. THIS PROSPECTUS SUPPLEMENT IS NOT AN OFFER TO SELL OR SOLICITATION
OF AN OFFER TO BUY THESE ORDINARY SHARES IN ANY CIRCUMSTANCES UNDER WHICH THE
OFFER OR SOLICITATION IS UNLAWFUL.
 
                               TABLE OF CONTENTS
 
                             PROSPECTUS SUPPLEMENT
 


                                                  PAGE
                                                  ----
                                               
Prospectus Supplement Summary...................   S-1
Risk Factors....................................   S-3
Dividends.......................................   S-8
Use of Proceeds.................................   S-8
Price Range of Ordinary Shares..................   S-9
Capitalization..................................   S-9
Selected Consolidated Financial Data............  S-10
Business........................................  S-11
Selling Shareholders............................  S-14
Underwriter.....................................  S-15
Legal Matters...................................  S-15
PROSPECTUS FOR SHARES OFFERED BY THE COMPANY
About this Prospectus...........................     2
Where You Can Find More Information.............     2
About Flextronics...............................     3
Enforcement of Civil Liabilities................     3
Risk Factors....................................     3
Use of Proceeds.................................     4
Description of Capital Shares...................     4
Taxation........................................     6
Plan of Distribution............................     8
Legal Matters...................................     8
Experts.........................................     8
PROSPECTUS FOR SHARES OFFERED BY
  SELLING SHAREHOLDERS
Where you can find more information.............   A-2
The Company.....................................   A-3
Enforcement of Civil Liabilities................   A-3
Risk Factors....................................   A-4
Selling Shareholders............................   A-8
Plan of Distribution............................   A-9
Legal Matters...................................   A-9

 
- ------------------------------------------------------
- ------------------------------------------------------
- ------------------------------------------------------
- ------------------------------------------------------
 
                           3,700,000 ORDINARY SHARES
 
                        [FLEXTRONICS INTERNATIONAL LOGO]
                    ----------------------------------------
                             PROSPECTUS SUPPLEMENT
                    ----------------------------------------
                     NATIONSBANC MONTGOMERY SECURITIES LLC
                             DATED DECEMBER 7, 1998
- ------------------------------------------------------
- ------------------------------------------------------