<PAGE>
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                  FORM 10-Q/A

(MARK ONE)

  /X/    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
         SECURITIES EXCHANGE ACT OF 1934

                 FOR THE QUARTERLY PERIOD ENDED APRIL 4, 1999,

                                       OR

  / /    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
         SECURITIES EXCHANGE ACT OF 1934

        FOR THE TRANSITION PERIOD FROM ______________ TO ______________.

                         COMMISSION FILE NUMBER: 1-4682

                            ------------------------

                           THOMAS & BETTS CORPORATION
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                            <C>
                  TENNESSEE                                     22-1326940
          (State of Incorporation)                 (I.R.S. Employer Identification No.)

            8155 T & B BOULEVARD
             MEMPHIS, TENNESSEE                                    38125
  (Address of principal executive offices)                      (Zip Code)
</TABLE>

                                 (901) 252-8000
              (Registrant's telephone number, including area code)

                            ------------------------

    Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes /X/  No / /

    Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

<TABLE>
<S>                                            <C>
        COMMON STOCK--$0.10 PAR VALUE               OUTSTANDING SHARES AT MAY 10, 1999
            (Title of each Class)                               56,865,494
</TABLE>

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

                           THOMAS & BETTS CORPORATION

                           CONSOLIDATED BALANCE SHEET
                                 (IN THOUSANDS)


<TABLE>
<CAPTION>
                                                               APRIL 4,     JANUARY 3,
                                                                 1999          1999
                                                              -----------   -----------
                                                              (UNAUDITED)    (AUDITED)
<S>                                                           <C>           <C>
                                        ASSETS
Current Assets:
  Cash and cash equivalents.................................  $   37,055    $   64,028
  Marketable securities.....................................      26,666        42,478
  Receivables, net..........................................     452,335       404,784
  Inventories:
    Finished goods..........................................     217,172       202,368
    Work-in-process.........................................      84,529        95,436
    Raw materials...........................................     190,805       171,837
                                                              ----------    ----------
                                                                 492,506       469,641
  Deferred income taxes.....................................      51,570        61,829
  Prepaid expenses..........................................      24,345        15,642
                                                              ----------    ----------
Total Current Assets........................................   1,084,477     1,058,402
Property, plant and equipment...............................   1,207,390     1,162,942
  Less accumulated depreciation.............................     560,586       531,920
                                                              ----------    ----------
    Property, plant and equipment--net......................     646,804       631,022
Intangible assets--net......................................     620,589       621,487
Investments in unconsolidated companies.....................     150,373       142,251
Other assets................................................      51,844        46,425
                                                              ----------    ----------
TOTAL ASSETS................................................  $2,554,087    $2,499,587
                                                              ==========    ==========
                         LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities:
  Notes payable.............................................  $   64,083    $   75,068
  Current maturities of long-term debt......................      23,201        22,589
  Accounts payable..........................................     274,220       262,483
  Accrued liabilities.......................................     159,598       155,815
  Income taxes..............................................      28,466        55,674
  Dividends payable.........................................      15,971        15,920
                                                              ----------    ----------
Total Current Liabilities...................................     565,539       587,549
Long-term debt..............................................     850,672       790,963
Other long-term liabilities.................................      97,361        93,788
Deferred income taxes.......................................      21,003        12,182

Shareholders' Equity:
  Common stock..............................................       5,764         5,678
  Additional paid-in capital................................     325,963       322,018
  Retained earnings.........................................     727,147       710,474
  Unearned compensation--restricted stock...................      (6,583)       (4,534)
  Accumulated other comprehensive income....................     (32,779)      (18,531)
                                                              ----------    ----------
Total Shareholders' Equity..................................   1,019,512     1,015,105
                                                              ----------    ----------
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY..................  $2,554,087    $2,499,587
                                                              ==========    ==========
</TABLE>



          See accompanying notes to consolidated financial statements.


                                       2
<PAGE>
                           THOMAS & BETTS CORPORATION

                       CONSOLIDATED STATEMENT OF EARNINGS
                      (IN THOUSANDS EXCEPT PER SHARE DATA)
                                  (UNAUDITED)


<TABLE>
<CAPTION>
                                                                  QUARTER ENDED
                                                              ---------------------
                                                              APRIL 4,    APRIL 5,
                                                                1999        1998
                                                              ---------   ---------
<S>                                                           <C>         <C>
Net sales...................................................  $612,011    $544,508

Costs and expenses:
  Cost of sales.............................................   435,550     383,412
  Marketing, general and administrative.....................   106,995      85,330
  Research and development..................................    12,475      13,303
  Amortization of intangibles...............................     4,574       4,382
  Provision (recovery)--restructured operations.............    (1,462)         --
                                                              --------    --------
                                                               558,132     486,427
                                                              --------    --------

Earnings from operations....................................    53,879      58,081

Income from unconsolidated companies........................     8,997       8,527

Other expense--net..........................................    14,996      12,856
                                                              --------    --------

Earnings before income taxes................................    47,880      53,752

Income taxes................................................    13,387      16,449
                                                              --------    --------

Net earnings................................................  $ 34,493    $ 37,303
                                                              ========    ========

Net earnings per share:
  Basic.....................................................  $   0.60    $   0.66
                                                              ========    ========
  Diluted...................................................  $   0.60    $   0.65
                                                              ========    ========

Average shares outstanding:
  Basic.....................................................    57,582      56,539
                                                              ========    ========
  Diluted...................................................    57,778      57,008
                                                              ========    ========

Cash dividends declared per share...........................  $   0.28    $   0.28
                                                              ========    ========
</TABLE>



          See accompanying notes to consolidated financial statements.


                                       3
<PAGE>
                           THOMAS & BETTS CORPORATION

                      CONSOLIDATED STATEMENT OF CASH FLOWS
                                 (IN THOUSANDS)
                                  (UNAUDITED)


<TABLE>
<CAPTION>
                                                                  QUARTER ENDED
                                                              ---------------------
                                                              APRIL 4,    APRIL 5,
                                                                1999        1998
                                                              ---------   ---------
<S>                                                           <C>         <C>
CASH FLOWS FROM OPERATING ACTIVITIES
Net earnings................................................  $  34,493   $ 37,303
Adjustments:
  Depreciation and amortization.............................     25,841     26,893
  Provision (recovery)--restructured operations.............     (1,462)        --
  Undistributed earnings from unconsolidated companies......     (8,997)    (4,337)
  Non-cash one-time charges.................................      5,123         --
  Deferred income taxes.....................................     20,153      5,227
  Changes in operating assets and liabilities, net:
    Receivables.............................................    (43,192)     9,694
    Inventories.............................................    (15,899)   (27,259)
    Accounts payable........................................      6,958    (36,912)
    Accrued liabilities.....................................     (8,148)   (11,894)
    Income taxes payable....................................    (24,716)    (7,264)
    Other...................................................    (13,073)    (2,118)
                                                              ---------   --------
Net cash used in operating activities.......................    (22,919)   (10,667)
                                                              ---------   --------
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of and investments in businesses, net of $7,245
  cash in 1999..............................................    (13,239)    (1,098)
Purchases of property, plant and equipment..................    (31,394)   (34,584)
Proceeds from sale of property, plant and equipment.........        160         --
Marketable securities acquired..............................         --    (10,330)
Proceeds from matured marketable securities.................     15,794     11,020
                                                              ---------   --------
Net cash used in investing activities.......................    (28,679)   (34,992)
                                                              ---------   --------
CASH FLOWS FROM FINANCING ACTIVITIES
Increase (decrease) in borrowings with original maturities
  less than 90 days.........................................    (10,985)     5,568
Proceeds from long-term debt and other borrowings...........    149,000     89,695
Repayment of long-term debt and other borrowings............   (101,054)    (7,137)
Stock options exercised.....................................      3,449      4,605
Cash dividends paid.........................................    (15,868)   (31,854)
                                                              ---------   --------
Net cash provided by financing activities...................     24,542     60,877
                                                              ---------   --------
EFFECT OF EXCHANGE-RATE CHANGES ON CASH.....................         83       (189)
                                                              ---------   --------
Net increase (decrease) in cash and cash equivalents........    (26,973)    15,029
Cash and cash equivalents at beginning of period............     64,028     45,226
                                                              ---------   --------
Cash and cash equivalents at end of period..................  $  37,055   $ 60,255
                                                              =========   ========
</TABLE>


          See accompanying notes to consolidated financial statements.

                                       4
<PAGE>
                           THOMAS & BETTS CORPORATION

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  (UNAUDITED)

1. BASIS OF PRESENTATION


    In the opinion of management, the accompanying consolidated financial
statements contain all adjustments necessary for the fair presentation of the
financial position as of April 4, 1999 and January 3, 1999, and the results of
operations and cash flows for the periods ended April 4, 1999 and April 5, 1998.


    Certain information and footnote disclosures normally included in financial
statements prepared in accordance with generally accepted accounting principles
have been condensed or omitted. These consolidated financial statements should
be read in conjunction with the financial statements and notes thereto included
in the Corporation's Annual Report on Form 10-K for the fiscal year ended
January 3, 1999. The results of operations for the periods ended April 4, 1999
and April 5, 1998 are not necessarily indicative of the operating results for
the full year.


    Amounts in 1998 have been restated to include the July 2, 1998 acquisition
of Telecommunications Devices, Inc., accounted for as a pooling of interests,
except for cash dividends per share, which reflect the Corporation's historical
per share amounts. Amounts have also been restated as of the beginning of 1999
to include the August 31, 1999 acquisition of L.E. Mason Co., accounted for as
an immaterial pooling of interests. That 1999 restatement increased
first-quarter 1999 net earnings by $0.2 million. In addition, after
consideration of matters described in Item 6 of the Corporation's third-quarter
1999 Form 10-Q, as amended by a Form 10-Q/A, the Corporation determined to make
further adjustments to restate its consolidated financial statements for the
fiscal quarter ended April 4, 1999. These further adjustments resulted in a
reduction of first-quarter 1999 net earnings of $3.7 million, $0.06 per share.


2. EARNINGS PER SHARE ("EPS")

    Basic EPS for each period are computed by dividing net earnings by the
weighted-average number of shares of common stock outstanding during the period.
Diluted EPS for each period are computed by dividing net earnings by the sum of
(1) the weighted-average number of shares outstanding during the period and
(2) the dilutive effect of the assumed exercise of stock options using the
treasury stock method.

    The following is a reconciliation of the numerators and denominators of the
per share computations:


<TABLE>
<CAPTION>
                                                                QUARTER ENDED
                                                            ---------------------
                                                            APRIL 4,    APRIL 5,
                                                              1999        1998
                                                            ---------   ---------
                                                            (IN THOUSANDS EXCEPT
                                                               PER SHARE DATA)
<S>                                                         <C>         <C>
Net earnings..............................................   $34,493     $37,303
                                                             -------     -------
Average shares outstanding................................    57,582      56,539
                                                             -------     -------
Basic EPS.................................................   $  0.60     $  0.66
                                                             =======     =======
Average shares outstanding................................    57,582      56,539
Plus assumed exercise of stock options....................       196         469
                                                             -------     -------
                                                              57,778      57,008
                                                             -------     -------
Diluted EPS...............................................   $  0.60     $  0.65
                                                             =======     =======
</TABLE>


                                       5
<PAGE>
                           THOMAS & BETTS CORPORATION

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                            (UNAUDITED) (CONTINUED)

3. COMPREHENSIVE INCOME

    Total comprehensive income and its components are as follows:


<TABLE>
<CAPTION>
                                                               QUARTER ENDED
                                                           ---------------------
                                                           APRIL 4,    APRIL 5,
                                                             1999        1998
                                                           ---------   ---------
                                                              (IN THOUSANDS)
<S>                                                        <C>         <C>
Net earnings.............................................  $ 34,493     $37,303

Foreign currency translation adjustments.................   (13,685)     (1,760)
Minimum pension liability adjustment.....................      (551)         --
Unrealized holding gains (losses) on securities..........       (12)         --
                                                           --------     -------
Comprehensive income.....................................  $ 20,245     $35,543
                                                           ========     =======
</TABLE>


4. ACQUISITIONS

    The Corporation completed one acquisition during the first quarter of 1999
for total consideration of approximately $20.0 million in cash. The acquisition
was accounted for under the purchase method of accounting; accordingly, its
results of operations have been included in the consolidated statement of
earnings since the date of acquisition. The aggregate purchase price has been
allocated to the assets and liabilities based on estimated fair values at the
date of acquisition and the excess of approximately $5.9 million was allocated
to goodwill. The goodwill is being amortized on a straight-line basis over 40
years.

5. RESTRUCTURING AND SPECIAL CHARGES

    During the third quarter of 1998, the Corporation recorded pretax
restructuring and special charges of $108.5 million primarily related to a
program to reduce costs by consolidating several facilities and product-line
operations, terminating employees at affected locations, downsizing
administrative functions and writing down idle facilities. The charges were
comprised of a $62.1 million provision for restructuring operations and $46.4
million of other special charges, of which $30.3 million was charged to cost of
sales

                                       6
<PAGE>
                           THOMAS & BETTS CORPORATION

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                            (UNAUDITED) (CONTINUED)

5. RESTRUCTURING AND SPECIAL CHARGES (CONTINUED)

and $16.1 million to marketing, general and administrative expense. The
components of those charges and usage through April 4, 1999 were:


<TABLE>
<CAPTION>
                                                                      CHARGES TO      REMAINING
                                                      CHARGES TO    RESERVES DURING   BALANCE AT
                                          ORIGINAL     RESERVES      FIRST QUARTER     APRIL 4,
                                          PROVISION   DURING 1998        1999            1999
                                          ---------   -----------   ---------------   ----------
<S>                                       <C>         <C>           <C>               <C>
Severance and employee related costs....   $ 26.6       $ (7.6)         $ (3.4)         $15.6
Property, plant and equipment
  write-offs............................     25.7         (7.0)           (0.4)          18.3
Other facility exit costs...............      9.8         (2.8)           (0.6)           6.4
                                           ------       ------          ------          -----
  Provision for restructured
    operations..........................     62.1        (17.4)           (4.4)          40.3
                                           ------       ------          ------          -----
Inventory write-offs related to
  restructuring.........................     25.6(1)     (14.4)           (4.6)           6.6
Costs related to previously idled
  facilities:
  Write-downs...........................      4.7(1)        --              --            4.7
  Carrying costs........................     10.4(2)      (2.2)             --            8.2
Other...................................      5.7(2)        --            (2.3)           3.4
                                           ------       ------          ------          -----
  Special charge........................     46.4        (16.6)           (6.9)          22.9
                                           ------       ------          ------          -----
  Total.................................   $108.5       $(34.0)         $(11.3)         $63.2
                                           ======       ======          ======          =====
</TABLE>


Charged to (1) cost of sales, and (2) marketing, general and administrative
expense.

    Severance and other employee-related costs involve actions that will result
in a net reduction of approximately 400 jobs, including administrative positions
at plants and corporate headquarters. As of April 4, 1999, the Corporation had
realized a net reduction of approximately 200 jobs. The property, plant and
equipment write-offs reduced to fair value the carrying amount of fixed assets
that were not relocated in conjunction with their associated manufacturing
processes. Assets written down as part of the cost-reduction program remain
classified as property, plant and equipment until idled; the adjusted carrying
value of the assets still in use was approximately $33.0 million. The effect of
suspending depreciation on facilities idled was $0.1 million of depreciation
expense reduction in the first quarter of 1999.

    Inventory write-offs primarily relate to items that became obsolete due to
modifications of manufacturing processes for product lines being relocated;
items not cost-effective to relocate; and, to a lesser degree, inventory
associated with discontinued products.

    Costs related to previously idled and written-down facilities were based on
management's current estimates of costs necessary to ultimately dispose of, and
satisfy obligations related to, such facilities. The majority of those are
lease-related costs, which will generally be incurred ratably over an eight-year
period.

    The cost-reduction programs commenced in 1998 are expected to be
substantially completed by year-end 1999, with disposal of idle facilities
anticipated by the end of 2000. Certain other costs, primarily relating to the
relocation of inventory, equipment and personnel, are not accruable until
incurred. Such costs, which were not included in the $108.5 million provision,
amounted to $2.6 million in 1999. Future revenues are not expected to be
significantly affected, since the cost-reduction programs are primarily intended
to relocate operations rather than discontinue operations.

                                       7
<PAGE>
                           THOMAS & BETTS CORPORATION

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                            (UNAUDITED) (CONTINUED)

5. RESTRUCTURING AND SPECIAL CHARGES (CONTINUED)


    During the fourth quarter of 1996 as part of the accounting for the
acquisition of Augat Inc., the Corporation recorded a restructuring charge of
$24.5 million for the integration of Augat and for initiatives affecting Augat
and other of the Corporation's operations. While most of these initiatives were
implemented, decisions were made not to execute all of the originally planned
phases of certain projects provided for by this charge. The decisions made in
the first quarter of 1999 resulted in reductions to the restructuring reserve in
the first quarter of 1999 of $1.5 million.


6. SEGMENT AND OTHER RELATED DISCLOSURES

    The Corporation has three reportable segments: Electrical, Electronic
Original Equipment Manufacturer (Electronic OEM) and Communications. Some
business activities cannot be classified in the aforementioned segments and are
shown under "Other." The Corporation's reportable segments are based on channels
to market, and represent the primary mode used to assess allocation of resources
and performance. Management evaluates each segment's profit or loss performance
based on earnings before interest, taxes, loss on sale of accounts receivable,
restructure and special charges and foreign exchange gains and losses.

SEGMENT INFORMATION


<TABLE>
<CAPTION>
                                                                  QUARTER ENDED
                                                              ---------------------
                                                              APRIL 4,    APRIL 5,
                                                                1999        1998
                                                              ---------   ---------
                                                                 (IN THOUSANDS)
<S>                                                           <C>         <C>
Net Sales:
  Electrical................................................  $332,282    $260,980
  Electronic OEM............................................   158,020     171,300
  Communications............................................    62,407      68,241
  All other.................................................    59,302      43,987
                                                              --------    --------
    Total...................................................  $612,011    $544,508
                                                              ========    ========

Segment Earnings:
  Electrical................................................  $ 45,093    $ 44,641
  Electronic OEM............................................    11,255      16,071
  Communications............................................    (1,308)      5,351
  Related to all other sales................................     6,204         200
                                                              --------    --------
    Total...................................................  $ 61,244    $ 66,263
                                                              ========    ========
</TABLE>


                                       8
<PAGE>
                           THOMAS & BETTS CORPORATION

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                            (UNAUDITED) (CONTINUED)

6. SEGMENT AND OTHER RELATED DISCLOSURES (CONTINUED)

    The following are reconciliations of the total of reportable segments to the
consolidated Corporation:

RECONCILIATION TO TOTAL CORPORATION


<TABLE>
<CAPTION>
                                                                  QUARTER ENDED
                                                              ---------------------
                                                              APRIL 4,    APRIL 5,
                                                                1999        1998
                                                              ---------   ---------
                                                                 (IN THOUSANDS)
<S>                                                           <C>         <C>
Net Sales:
  Total reportable segment net sales........................  $552,709    $500,521
  Other sales...............................................    59,302      43,987
                                                              --------    --------
    Total...................................................  $612,011    $544,508
                                                              ========    ========

Earnings Before Income Taxes:
  Total reportable segment earnings.........................  $ 55,040    $ 66,063
  Earnings on other sales...................................     6,204         200
  Restructure and special charges...........................     1,462          --
  Interest expense..........................................   (15,982)    (10,927)
  Loss on sale of receivables...............................    (2,265)     (2,387)
  Interest income...........................................     3,292       1,328
  Foreign currency exchange gains (losses)..................       129        (525)
                                                              --------    --------
    Total...................................................  $ 47,880    $ 53,752
                                                              ========    ========
</TABLE>


                                       9
<PAGE>
ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF RESULTS OF OPERATIONS AND
         FINANCIAL CONDITION

RESULTS OF OPERATIONS


    For the quarter ended April 4, 1999, the Corporation had net earnings of
$34.5 million compared with $37.3 million in the same 1998 period. Diluted
earnings per share (EPS) were $0.60, five cents below diluted EPS of $0.65 in
1998's first quarter, and basic EPS were $0.60 versus $0.66 in the prior-year
quarter.



    First-quarter net sales grew 12.4% to $612.0 million from 1998's $544.5
million. Contributions from acquisitions over the past year, most significantly
Kaufel Group, Ltd., increased sales by 13.6%, helping to offset lower
year-over-year sales in the Electronic OEM and Communications segments.


    On a geographic perspective, sales to European and Latin American customers
improved dramatically in the quarter. European sales rose 45.8% from last year's
quarter due to the addition of sales from electrical acquisitions and higher
electronic component sales volumes. Sales in Latin America grew 143.1% year over
year as a result of increased penetration of core electrical and electronic
markets. Sales in Canada were 31.9% higher than 1998's first quarter as a result
of the acquisition of Kaufel in late 1998. Sales to customers within the
Asia/Pacific region declined 8.9% versus the prior year as the year-over-year
negative growth of that region's economies overpowered additional sales from
acquisitions.


    The consolidated gross margin declined from 1998's level of 29.6% to 28.8%
because of lower selling prices and unfavorable product mix in the Electronics
OEM and Communications segments. Consolidated operating margin decreased to 8.8%
from 10.7% as a result of acquisition-related year-over-year increases in
marketing, general and administrative expenses as a percentage of sales and the
decline in gross margin.



    First-quarter income from unconsolidated companies increased 5.5% from the
prior-year as a result of continued strong equity income from the Corporation's
interest in unconsolidated companies in the Electrical segment. Other
expense-net was $2.1 million higher than the prior year primarily due to higher
acquisition-related interest expense. The Corporation's effective tax rate for
the first quarter was 28%. That rate compared with an effective rate of 30.6% in
the 1998 quarter and was lower as Thomas & Betts continued to enjoy the benefits
of tax planning initiatives implemented during 1997 and 1998.


COST-REDUCTION PROGRAM

    Cost-reduction savings, net of related project expenses, in the quarter
exceeded net savings anticipated at the outset of the cost-reduction program in
the third quarter of 1998, as shown in the following table:

<TABLE>
<CAPTION>
                                                              FIRST QUARTER 1999
                                                            ----------------------
                                                            ORIGINALLY
                                                            ANTICIPATED    ACTUAL
                                                            -----------   --------
                                                                (IN MILLIONS)
<S>                                                         <C>           <C>
SAVINGS
  Salaries................................................      $ 2.4      $ 2.0
  Manufacturing Labor.....................................        6.1        5.2
  Depreciation............................................        0.1        0.1
  Overhead................................................       (1.0)      (0.6)
                                                                -----      -----
    Total.................................................      $ 7.6      $ 6.7
RELATED PROJECT EXPENSES
  Net Savings.............................................       (7.6)      (2.6)
                                                                -----      -----
                                                                $  --      $ 4.1
                                                                =====      =====
</TABLE>

                                       10
<PAGE>
    Net savings in the first quarter exceeded original expectations primarily
because lower project expenses were incurred than originally anticipated.
Project expenses are primarily relocation and training costs which must be
expensed as incurred since they provide future value. The lower level of project
expenses actually incurred in the first quarter reflects re-sequencing of the
particular projects undertaken to obtain a greater initial benefit. Net savings
for the second quarter are expected to be less than $1 million, reflecting
higher project expenses; however, for full year 1999 net savings are expected to
be substantially the same as originally anticipated at the outset of the
program.

    Cash disbursements which were charged against reserves for severance and
facility exit costs in the first quarter of 1999 were approximately $4.0 million
compared to $7.2 million originally anticipated. The lower expenditure reflects
the later timing of facility closures in the first quarter.

    Asset write-offs in the first quarter of 1999 were less than originally
anticipated because sales of facilities to be idled, and therefore their related
write-offs, have not occurred as rapidly as originally planned.

SEGMENT RESULTS


    Sales of the Electrical segment increased 27.3% to $332.3 million for the
quarter, and segment earnings rose 1.0% to $45.1 million. Sales from
acquisitions, together with strong demand in utility markets, accounted for the
segment's sales growth. The segment's earnings growth was less than the sales
growth due to changes in the mix of products sold. Electrical sales improved
month-over-month throughout the quarter, and demand in Canada, where the
Corporation records 15% of its Electrical sales, also began to recover late in
the quarter in response to higher commodity prices that have fueled an upturn of
industrial and commercial construction in that country.



    First-quarter sales of the Electronic OEM segment were $158.0 million, 7.8%
lower than the 1998 period. First-quarter segment earnings were $11.3 million,
or 30.0% lower compared with 1998's first-quarter results. Volume decreases in
components sold to computer and automotive manufacturers and lower prices
accounted for the decline. In the quarter the Corporation sold $8.7 million of
products based on its Metallized Particle Interconnect (MPI) technology and
shipped the first production quantities of its lithium-polymer ion (LPI) battery
packs.



    Sales of the Communications segment were $62.4 million, 8.5% lower than
1998's first-quarter level. Uncertainty among U.S. telecommunications customers
as a result of industry mergers and depressed foreign economies caused the
decrease in segment sales. First-quarter segment earnings were well below those
of 1998's quarter with the decline due primarily to an unfavorable shift of
sales to lower-margin cable television amplifier products and the lower sales to
telecommunications customers.



    Other sales in the first quarter totaled $59.3 million, 34.8% above 1998's
first-quarter level. Sales of steel structures rose dramatically year-over-year
compared with weak prior-year sales as demand from traditional utility
customers' projects returned to more normal levels and sales of wind-generation
towers remained strong. Earnings on other sales increased to $6.2 million,
$6.0 million over 1998's quarter, due to more effective capacity utilization and
expense control in the manufacture of steel structures and heating units.


LIQUIDITY AND CAPITAL RESOURCES


    Net cash used by operating activities was $22.9 million through the first
three months of 1999. Accounts receivable rose $43.2 million from year-end 1998
primarily as a result of:


    - temporary increases associated with conversions of the Corporation's
      various financial systems;

    - payment of volume incentive discounts to customers for their 1998
      purchases, reducing accruals for discounts which are recorded as contra
      assets offsetting gross receivables;

                                       11
<PAGE>

    - the acquisitions of Ocal and L.E. Mason; and


    - seasonal build-up of accounts receivable generated by the heating business
      due to its annual pre-season sales program.


    Inventory levels were $15.9 million higher than year-end levels due to three
factors:



    - the acquisitions of Ocal and L.E. Mason;


    - ramp-up for a new product launch; and

    - safety stock that the Corporation held to avoid customer service
      disruptions as it moved product lines from one plant to another to achieve
      lower manufacturing costs.


    Accounts payable increased $7.0 million during the quarter, reflecting
additional purchases in support of higher sales and inventory levels.


    Capital expenditures for the first quarter of 1999 totaled $31.4 million, a
decrease of 9.2% versus the same period of 1998. The spending decline primarily
resulted from lower spending on information systems compared with the prior
year's high levels. Dividends paid during the three months of 1999 totaled
$15.9 million for dividends declared in the fourth quarter of 1998.

    As of April 4, 1999, marketable securities, cash and equivalents totaled
$63.7 million, compared with $106.5 million as of January 4, 1999. The cash
balance was reduced as a result of two factors:

    - reduced cash balance requirements while still retaining the same tax
      benefits related to funds held in Puerto Rico; and

    - improved banking and cash management arrangements related to recent
      acquisitions.

    Thomas & Betts maintains a commercial paper program, which is backed by
$500 million of revolving-credit agreements. At April 4, 1999, $135 million of
commercial paper was outstanding. Management believes that its external
financial resources and internally generated funds are sufficient to meet the
Corporation's immediate short-term capital needs. Longer term, Thomas & Betts
will continue to finance future acquisitions through issuance of private or
public debt, common stock, other equity instruments, internally generated funds
or a combination of those sources.

    On January 5, 1999, the Corporation completed its acquisition of Ocal, Inc.,
a manufacturer of PVC-coated conduit and components for use in corrosive
industrial environments, for cash of approximately $20 million. Ocal's
manufacturing facility is located in Mobile, AL.

    In February 1999, the Corporation issued approximately $150 million of
10-year medium-term notes at par with a coupon of 6.39%. The Corporation used
the proceeds from that sale to reduce borrowings under its commercial paper
program and under uncommitted lines of credit.

OTHER EVENTS

    On January 27, 1999, the Corporation entered into an agreement to acquire
the outstanding common stock of AFC Cable Systems, Inc. (AFC) in a
stock-for-stock merger valued at approximately $490 million. AFC is a Rhode
Island-based manufacturer of electrical and communications products and systems
for commercial and industrial buildings. The Corporation is hopeful that the
transaction, which is currently pending before the SEC and is subject to
approval by the shareholders of both companies, will be completed in the first
half of 1999. It is expected to be accounted for as a pooling of interests.

YEAR-2000 READINESS PROGRAM

    Thomas & Betts is actively engaged in a corporate-wide program to ensure its
systems and products are Year-2000 compliant. The Year-2000 issue is the result
of computer programs being written using two

                                       12
<PAGE>
digits rather than four to define the applicable year. As a result, computer
programs that have time-sensitive software are at risk to recognize a date using
"00" as the year 1900 rather than the year 2000. Thomas & Betts is taking steps
that it believes will ensure no disruption to its operations. In 1997, the
Corporation began a worldwide-technology upgrade of its order-entry and
financial-reporting computer systems. As part of that project, Thomas & Betts
has completed an assessment of its Year-2000 issue and is modifying or replacing
portions of its software so that its computer systems will function properly
with respect to dates in the year 2000 and thereafter.

    Thomas & Betts' plan to resolve the Year-2000 issue involves four phases:
assessment, remediation, testing and implementation. As of September 1998,
Thomas & Betts had completed its assessment of all significant computer systems
that could be affected by the Year-2000 issue. The assessment indicated that
many of the Corporation's important information technology systems could be
affected, and that software used in certain manufacturing equipment was at risk.
Thomas & Betts is currently in the process of correcting those systems and
manufacturing equipment that present a risk.

    At April 4, 1999, Thomas & Betts had completed 94% of the remediation phase
for all non-compliant legacy programs, and expects to complete remediation of
these programs by July 1, 1999. After completing the reprogramming and
replacement of software, the Corporation's plans call for testing and
implementing its information technology systems. Thomas & Betts has implemented
core order entry, distribution, pricing, plant and financial systems that are
Year-2000 compliant. The Corporation expects to complete the testing phase by
July 1, 1999, with all remediated systems fully implemented by September 1,
1999.

    With respect to operating equipment, Thomas & Betts had completed an
assessment of equipment that could be affected by the Year-2000 issue, had
completed 75% of the remediation phase and had completed 75% of the testing of
that equipment at April 4, 1999. Once testing is completed, the operating
equipment will be ready for immediate use. Thomas & Betts expects to complete
its equipment remediation efforts by July 1, 1999, and testing and implementing
of all affected equipment by September 1, 1999.

    Thomas & Betts has surveyed its important suppliers, vendors and customers,
either by mail or telephone, to assess their Year-2000 readiness. To date, the
Corporation is not aware of any problems within those groups that would
materially affect results of Thomas & Betts' operations.

    The Corporation is utilizing both internal and external resources to
reprogram or replace, test and implement the software and operating equipment
for Year-2000 modifications. As part of the previously mentioned
worldwide-technology upgrade that began in 1997, the Corporation has been and is
installing new systems with greatly enhanced functionality that will also solve
potential Year-2000 problems in those areas. Management anticipates that its
costs to modify existing software for Year-2000 compliance will approximate
$2 million, and to date, Thomas & Betts has spent approximately 75% of that
amount on Year-2000 issues.

    Thomas & Betts' plans to complete Year-2000 modifications are based on
management's best estimates, which were derived utilizing numerous assumptions
of future events, including the continued availability of certain resources and
other factors. Estimates of the status of completion and the expected completion
dates are based on hours expended to date compared to total expected hours.
However, there can be no guarantee that those estimates will be achieved, and
actual results could differ materially from those anticipated. Specific factors
that might cause material differences include, but are not limited to, the
availability and cost of personnel training in this area, and the ability to
locate and correct all relevant computer codes and similar uncertainties.

    The Corporation has contingency plans to address situations that may result
if the Corporation is unable to achieve Year-2000 readiness of its critical
operating systems. Those contingency plans cover the critical order processing
and distribution systems, as well as plant operating systems. A majority of
those plans involve redundant systems. For example, the Corporation is
remediating existing systems in parallel with development of Year-2000 compliant
replacement systems for order processing and distribution.

                                       13
<PAGE>
    In the event that the Corporation's actions to correct potential Year-2000
issues are incomplete and its contingency plans fail, the incorrect recognition
of the year 2000 by time-sensitive software could result in a system failure or
miscalculations causing disruptions of operations--including, among other
things, a temporary inability to process orders, prepare invoices or engage in
normal business activities. The Corporation expects that any such disruption
would be temporary and likely not material, as any previously undetected root
cause for such disruption could likely be identified and fixed in a relatively
short period of time. However, if both the Corporation's Year-2000 solution and
contingency plans fail for a critical system for a prolonged period, the impact
on the Corporation would be material.

    Despite assurances from outside parties of their timely readiness, the
Corporation cannot ensure that its suppliers, vendors and customers will resolve
all Year-2000 issues. Given the responses to date from its suppliers, vendors
and customers, Thomas & Betts believes it is unlikely that a large number of
them will experience significant problems due to unresolved Year-2000 issues.
Should such an event occur, the Corporation can adjust its order processing
cycle to accommodate manual orders from its customers while those third parties
resolve outstanding issues. Consequently, the failure by some parties to
complete their Year-2000 readiness process would not likely have a material
impact on the Corporation. In the event that a large number of customers suffer
Year- 2000 compliance issues over a prolonged period, the impact on the
Corporation would be material.

EURO CONVERSION

    On January 1, 1999, 11 of the 15 member countries of the European Union
established fixed-conversion rates between their existing sovereign currencies
and the euro, and began a three-and-one-half-year effort to fully adopt the euro
as their common legal currency.

    Thomas & Betts is continuing to assess the potential impact on the
Corporation that may result from the euro conversion. In addition to tax and
accounting considerations, the Corporation is assessing the potential impact
from the euro conversion in a number of areas, including: (1) the technical
challenges to adapt information technology and other systems to accommodate
euro-denominated transactions; (2) the competitive impact of cross-border price
transparency, which may make it more difficult for businesses to charge
different prices for the same products on a country-by-country basis; (3) the
impact on currency exchange costs and currency exchange-rate risks; and (4) the
impact on existing contracts. Thomas & Betts cannot yet predict the anticipated
impact of the euro conversion on its operations.

                                       14
<PAGE>
PART II. OTHER INFORMATION

                           THOMAS & BETTS CORPORATION

ITEM 5.  OTHER INFORMATION

(a) Forward-Looking Statements May Prove Inaccurate

    This document includes various forward-looking statements about Thomas  &
    Betts which are subject to risks and uncertainties. Forward-looking
    statements include information concerning future results of operations and
    cost savings. Statements that contain words such as "believes," "expects,"
    "anticipates," "intends," "estimates" or similar expressions are
    forward-looking statements. These forward-looking statements are subject to
    risks and uncertainties, and many factors could affect the future financial
    results of Thomas & Betts. Accordingly, actual results may differ materially
    from those expressed or implied by the forward-looking statements contained
    in this document. For these statements, the Corporation claims the
    protection of the safe harbor for forward-looking statements contained in
    the Private Securities Litigation Reform Act of 1995.

    There are many important factors that could cause actual results to differ
    materially from those in forward-looking statements, some of which are
    beyond the control of Thomas & Betts. These factors include, but are not
    limited to:

       - Negative economic conditions in the countries where Thomas & Betts
         sells its products which may affect performance;

       - Materially adverse changes in economic or industry conditions generally
         or in the specific markets served by Thomas & Betts, and economic
         slowdown in the U.S. or economic slowdowns in Thomas  & Betts' major
         offshore markets, including Europe (particularly Germany and the United
         Kingdom), Canada, Japan and Taiwan;

       - Adverse regulatory, environmental, monetary or other governmental
         policies in the U.S. and abroad which could result in currency
         fluctuations--including fluctuations in the Canadian dollar, German
         mark, Japanese yen, Swiss franc and British pound--which, in turn,
         could adversely affect Thomas & Betts' revenues and cost of sales;

       - Significant changes in any number of governmental policies domestically
         and abroad which could create trade restrictions, patent enforcement
         issues, adverse tax-rate changes and changes to tax treatment of items
         such as tax credits, withholding taxes, transfer pricing and other
         income and expense recognition for tax purposes, including changes in
         taxation on income generated in Puerto Rico;

       - Changes in environmental regulations, including emissions to air,
         discharge to waters and the generation and handling of waste, which
         could impact expectations of remediation expenses, and potentially
         significant expenditures required to comply with environmental
         regulations and policies that may be adopted or imposed in the future;

       - Rapid expansion through acquisitions and joint ventures which may
         result in integration difficulties;

       - Inflationary pressures which could raise interest rates and
         consequently Thomas & Betts' cost of funds;

       - Disagreements and changes in its relationships with its joint venture
         partners and changes in financial results from its joint ventures and
         other equity investments, including ventures in Taiwan, Japan, Belgium,
         Egypt and the U.S.;

                                       15
<PAGE>
       - Strain on management resources and on other resources because of
         continued rapid growth of the Corporation;

       - Undiscovered liabilities arising from acquired businesses;

       - Future acquisitions which could result in potentially dilutive
         issuances of equity securities, the incurrence of debt and contingent
         liabilities and amortization expenses related to goodwill and other
         intangible assets, which materially adversely affect operating results
         and financial condition;

       - Competition which may negatively affect financial performance;

       - Increased downward pressure on the selling prices for Thomas & Betts'
         products;

       - Unforeseeable changes in customer demand for various products of
         Thomas & Betts, which could affect Thomas & Betts' overall product mix,
         margins, plant utilization levels and asset valuations;

       - Availability of raw materials (especially steel, copper, zinc,
         aluminum, gold and plastic resins) and significant price fluctuations
         in the cost of raw materials which could adversely affect Thomas &
         Betts' financial results;

       - Delayed cost-reduction initiatives or unforeseen difficulties in
         completing cost-reduction actions, including disposal of idle
         facilities, geographic shifts of production locations and closure of
         redundant administrative facilities; and

       - Failure of Year 2000 date-sensitive logic in computer programs and
         equipment within Thomas & Betts or third parties with whom Thomas &
         Betts does business which may disrupt business activities and
         operations.

ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

(a) The following exhibits are filed as part of this form:

    (27.1)  Financial Data Schedule (for SEC use only)

    (27.2)  Financial Data Schedule (for SEC use only)

(b) Reports on Form 8-K

    On February 1, 1999, the Corporation filed a current report on Form 8-K,
    Items 5 and 7, announcing that the Corporation had entered into a definitive
    agreement to acquire AFC Cable Systems, Inc. in a stock-for-stock merger.

    On February 5, 1999, the Corporation filed a current report on Form 8-K,
    Items 5 and 7, announcing the Corporation's financial results for the fiscal
    year ended January 3, 1999.

    On February 12, 1999, the Corporation filed a current report on Form 8-K,
    Items 5 and 7, announcing that the Corporation's Board of Directors amended
    the Bylaws of the Corporation and filing certain documents in connection
    with the issuance of medium-term notes.

                                       16
<PAGE>
                           THOMAS & BETTS CORPORATION

                                   SIGNATURES

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

                           THOMAS & BETTS CORPORATION
                                  (Registrant)


<TABLE>
<S>    <C>                                     <C>
DATE:  January 3, 2000                         /s/ FRED R. JONES
       -------------------------------         -------------------------------------------
                                               Fred R. Jones
                                               Vice President--Chief Financial Officer
</TABLE>


                                       17