<PAGE>   1
             FORM 10-Q. - QUARTERLY REPORT UNDER SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                   FORM 10Q/A

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

For the quarterly period ended June 30, 1998


Commission File No. 0-25490


                                    KTI, INC.
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                                       <C>
           New Jersey                                           22-2665282
(State or other jurisdiction of                              (I.R.S. Employer
incorporation or organization)                            Identification Number)


7000 Boulevard East
Guttenberg, New Jersey                                                  07093
(Address of principal executive offices)                              (Zip code)
</TABLE>


                                 (201) 854-7777
               (Registrants 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 registrant's classes of
common stock, as of the latest practicable date:

        Common Stock, No Par Value         9,761,773 Shares as of August 7, 1998
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
Item Number and Caption                                                              Page Number
-----------------------                                                              -----------
<S>                                                                                  <C>
PART I

Item 1.  Financial Statements                                                                  2
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
          of Operations                                                                        9


PART II

Item 1.  Legal Proceedings                                                                    15
Item 2.  Changes in Securities                                                                15
Item 3.  Defaults Upon Senior Securities                                                      15
Item 4.  Submission of Matters to a Vote of Security Holders                                  15
Item 5.  Other Information                                                                    15
Item 6.  Exhibits and Reports on Form 8K                                                      16
</TABLE>


                                       1
<PAGE>   3
PART I - FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                                    KTI, INC.
                           CONSOLIDATED BALANCE SHEET
                      (IN THOUSANDS, EXCEPT SHARE AMOUNTS)

<TABLE>
<CAPTION>
                                                                              JUNE 30,             DECEMBER 31,
                                                                                1998                   1997
                                                                         -------------------   ---------------------
                                                                             (UNAUDITED)
                                  ASSETS
<S>                                                                      <C>                   <C>
Current Assets
     Cash and cash equivalents                                                     $ 10,027                $ 11,181
     Restricted funds                                                                16,367                  13,103
     Accounts receivable, net of allowances of
         $670 and $294                                                               21,974                  22,126
     Consumables and spare parts                                                      4,156                   4,041
     Inventory                                                                        2,044                   1,219
     Notes receivable--officers/shareholders and affiliates                             516                      29
     Other receivables                                                                  795                     461
     Deferred taxes                                                                       -                   2,751
     Other current assets                                                             1,286                     793
                                                                         -------------------   ---------------------
         Total current assets                                                        57,165                  55,704

Restricted funds                                                                      4,851                   6,527
Notes receivable - officers/shareholders and affiliates                                  86                      81
Other receivables                                                                       204                     271
Deferred costs, net of accumulated amortization
     of $885 and $676                                                                 4,690                   2,916
Goodwill and other intangibles, net of accumulated amortization
     of $1,610 and $778                                                              23,319                  17,483
Other assets                                                                          9,192                   1,768
Deferred project development costs                                                      932                     932
Property, equipment and leasehold improvements, net of
     accumulated depreciation of $21,693 and $17,837                                168,590                 156,801
                                                                         -------------------   ---------------------

     Total assets                                                                 $ 269,029               $ 242,483
                                                                         ===================   =====================

                   LIABILITIES AND STOCKHOLDERS' EQUITY
Current Liabilities
     Accounts payable                                                               $ 7,842                 $ 8,779
     Accrued expenses                                                                 2,272                   3,825
     Debt, current portion                                                            6,524                  19,794
     Income taxes payable                                                               797                     165
     Other current liabilities                                                        2,019                   1,184
                                                                         -------------------   ---------------------
         Total current liabilities                                                   19,454                  33,747

Other liabilities                                                                     5,434                   1,918
Debt, less current portion                                                          103,667                  74,473

Minority interest                                                                    24,176                  22,105
Deferred revenue                                                                     34,474                  37,500
Deferred taxes                                                                          899                       -

Commitments and contingencies

Stockholders' equity
Preferred stock; 10,000,000 shares authorized;
     Series A, par value $8 per share, 447,500 shares authorized, issued and
      outstanding in 1997                                                                --                   3,732
     Series B, par value $25 per share, 8.75%, 880,000 shares authorized,
      856,000 shares issued and outstanding in 1998 and 1997                         21,400                  21,400
Common stock, no par value (stated value $.01 per share); authorized 40,000,000
     and 20,000,000 in 1998 and 1997, respectively;
     issued and outstanding:  9,683,158 in 1998, 8,912,630 in 1997                       96                      89
Additional paid-in capital                                                           58,889                  52,762
Retained earnings (deficit)                                                             540                 (5,243)
                                                                         -------------------------------------------
Total stockholders' equity                                                           80,925                  72,740
                                                                         -------------------------------------------
     Total liabilities and stockholders' equity                                   $ 269,029               $ 242,483
                                                                         ===========================================
</TABLE>

     See accompanying notes.

                                       2
<PAGE>   4
                                    KTI, INC.
                      CONSOLIDATED STATEMENT OF OPERATIONS
               (IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)
                                   (UNAUDITED)

<TABLE>
<CAPTION>
                                                         THREE MONTHS ENDED                    SIX MONTHS ENDED
                                                               JUNE 30,                             JUNE 30,
                                                         1998             1997             1998                1997
                                                     --------------   -------------    --------------    ------------------
<S>                                                  <C>              <C>              <C>               <C>
Revenues:
    Waste-to-energy:
       Electric power and steam                            $23,699         $10,704           $34,112               $20,212
       Waste processing                                      8,951           7,906            17,032                15,723
    Recycling                                               16,808           1,871            35,946                 3,144
                                                     ------------------------------    ------------------------------------
                Total revenues                              49,458          20,481            87,090                39,079

Costs and expenses:
    Electric power, steam and waste processing              15,891          11,256            26,645                 21,751
    Recycling                                               16,300           1,730            33,722                  2,951
    General and administrative                               2,031           1,118             3,113                  2,163
    Depreciation and amortization                            2,608           2,254             5,065                  4,474
    Interest, net                                            1,550           1,325             3,060                  2,325
                                                     --------------   -------------    --------------    -------------------
               Total costs and expenses                     38,380          17,683            71,605                 33,664

Income before minority interest, income
    tax provision and extraordinary item                    11,078           2,798            15,485                  5,415
    Minority interest                                        2,509              26             3,578                    381
    Pre-acquisition earnings of PERC                             -           1,996                 -                  2,899
                                                     -----------------------------------------------------------------------
Income before income tax provision and
   extraordinary item                                        8,569             776            11,907                  2,135
    Income tax provision                                     3,347               -             4,693                      -
                                                     --------------   -------------    --------------    -------------------
Income before extraordinary item                             5,222             776             7,214                  2,135
    Extraordinary item- Loss on early
    extinguishment of debt, net of minority
    interest and income taxes                                  495               -               495                      -
                                                     --------------   -------------    --------------    -------------------
Net income                                                   4,727             776             6,719                  2,135
    Accretion and accrued and paid dividends
    on preferred stock                                         469             499               978                    499
                                                     --------------   -------------    --------------    -------------------
Net income available to common shareholders                 $4,258            $277            $5,741                 $1,636
                                                     ==============   =============    ==============    ===================

Earnings per common share:

Basic:
    Income before extraordinary item                         $0.49           $0.04             $0.66                  $0.24
       Extraordinary item                                    $0.05              --             $0.05                     --
                                                     -------------    -------------    --------------    -------------------
    Net income                                              $0.44            $0.04             $0.61                  $0.24

    Weighted average number of shares used in
    calculation                                          9,614,163       6,984,926         9,424,451              6,868,993

Diluted:
    Income before extraordinary item                         $0.42           $0.04             $0.59                  $0.23
       Extraordinary item                                    $0.04              --             $0.04                     --
                                                     --------------   -------------    --------------    -------------------
    Net income                                               $0.38           $0.04             $0.55                  $0.23

    Weighted average number of shares used
    in calculation                                      12,344,172       7,260,467        12,275,785              7,219,758
</TABLE>

                                        3

    See accompanying notes.
<PAGE>   5
                                    KTI, INC.
                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
                                   (UNAUDITED)

<TABLE>
<CAPTION>
                                                                             Six months ended June 30,
                                                                            1998                 1997
                                                                       ----------------    -----------------
<S>                                                                    <C>                 <C>
OPERATING ACTIVITIES
Net income                                                                     $ 6,719              $ 2,135
Adjustments to reconcile net income to net cash
      provided by (used in) operating activities:
    Depreciation and amortization                                                5,065                2,052
    Minority interest, net of distributions                                      2,071                  381
    Deferred revenue                                                            (3,026)              (3,102)
    Deferred taxes                                                               3,650                    -
    Provision for losses on accounts receivable                                    570                   47
    Interest accrued and capitalized on debt                                       701                  833
    Gain on sale of assets                                                        (30)                  (1)
    Loss on early extinguishment of debt                                           495                    -
    Securitiy received for sale of power                                        (3,814)                   -
    Changes in operating assets and liabilities:
      Accounts receivable                                                        1,095              (1,743)
      Management fees receivable                                                     -                  370
      Consumables, spare parts and inventories                                   (712)                (633)
      Other assets                                                             (4,032)                (227)
      Notes and other receivables                                                (263)                  440
      Accounts payable and accrued expenses                                    (3,620)                (297)
      Income taxes payable                                                         382                    -
      Other liabilities                                                          3,075                (652)
                                                                       ----------------    -----------------
Net cash provided by (used in) operating activities                              8,326                (397)

INVESTING ACTIVITIES
Additions to property, equipment and leasehold improvements                    (4,443)                (729)
Proceeds from sale of assets                                                        33                    2
Net changes in restricted funds                                                (1,483)                (995)
Purchase of businesses, net of cash acquired                                  (16,468)                    -
Notes receivable--affiliates                                                     (492)                (421)
                                                                       ----------------    -----------------
Net cash used in investing activities                                         (22,853)              (2,143)

FINANCING ACTIVITIES
Deferred financing costs                                                       (2,995)                (998)
Proceeds from issuance of debt                                                  46,995                9,133
Net borrowings on lines of credit                                               19,267                5,000
Proceeds from exercise of warrants                                                 995                    -
Proceeds from exercise of stock options                                          1,365                    -
Proceeds from sale of common stock                                                   -                  370
Proceeds from sale of preferred stock                                                -                3,855
Dividends paid on preferred stock                                                (936)                    -
Principal payments on debt                                                    (51,318)             (16,868)
                                                                       ----------------    -----------------
Net cash provided by financing activities                                       13,373                  492

Decrease in cash and cash equivalents                                          (1,154)              (2,048)
Cash and cash equivalents at beginning of period                                11,181                5,227
                                                                       ----------------    -----------------
Cash and cash equivalents at end of period                                    $ 10,027              $ 3,179
                                                                       ================    =================
</TABLE>

            -Continued-


                                       4
<PAGE>   6
                                    KTI, INC.
               CONSOLIDATED STATEMENTS OF CASH FLOWS--(CONTINUED)
                                 (IN THOUSANDS)
                                   (UNAUDITED)



<TABLE>
<S>                                                                   <C>                 <C>
       SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
       Interest paid                                                             $ 2,563             $   -
                                                                      =================== =================

       NON CASH INVESTING AND FINANCE ACTIVITIES
       Accretion on Class A Preferred Stock                                      $    42             $ 499
                                                                      =================== =================
</TABLE>

       See accompanying notes.


                                       5
<PAGE>   7
                                    KTI, INC.
                 CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
               (IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)


<TABLE>
<CAPTION>
                                               SERIES A             SERIES B
                                           PREFERRED STOCK      PREFERRED STOCK
                                            SHARES   AMOUNT    SHARES     AMOUNT
                                            ------   ------    ------     ------
<S>                                        <C>         <C>     <C>        <C>
Balance at December 31, 1996                       -   $   -          -       $   -
  Net income                                       -       -          -           -
  Issuance of Series A Preferred Stock                                             
   and common stock purchase warrants        487,500   3,376          -           -
  Accretion of Series A Preferred Stock            -     700          -           -
  Issuance of Series B Preferred Stock
   and common stock purchase warrants              -       -    856,000      21,400
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                           -       -          -           -
     Exercise of warrants                          -       -          -           -
     Conversion of debt                            -       -          -           -
     Conversion of preferred stock          (40,000)   (344)          -           -
     Employee savings plan contribution            -       -          -           -
     Business combinations                         -       -          -           -
  Dividends paid on Series B Preferred
   Stock                                           -       -          -           -
                                          -----------------------------------------
Balance at December 31, 1997                 447,500   3,732    856,000      21,400
  Net income                                       -       -          -           -
  Accretion of Series A Preferred Stock            -      42          -           -
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                           -       -          -           -
     Exercise of warrants                          -       -          -           -
     Conversion of debt                            -       -          -           -
     Conversion of preferred stock         (447,500) (3,774)          -           -
     Employee savings plan contribution            -       -          -           -
  Dividends paid on Series B Preferred
   Stock                                           -       -          -           -
                                          -----------------------------------------

Balance at June 30, 1998                           -  $    -    856,000   $  21,400
                                          =========================================
<CAPTION>
                                                                         ADDITIONAL
                                               COMMON STOCK                PAID IN
                                          SHARES         AMOUNT            CAPITAL
                                          ------         ------            -------
<S>                                       <C>            <C>             <C>
Balance at December 31, 1996               6,836,766          $   68            $ 38,576
  Net income                                       -               -                   -
  Issuance of Series A Preferred Stock                                                  
   and common stock purchase warrants              -               -                 422
  Accretion of Series A Preferred Stock            -               -               (700)
  Issuance of Series B Preferred Stock
   and common stock purchase warrants              -               -             (1,416)
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                      85,353               1                 502
     Exercise of warrants                    692,771               7               3,611
     Conversion of debt                      618,609               6               4,901
     Conversion of preferred stock            40,000               1                 343
     Employee savings plan contribution        4,117               -                  35
     Business combinations                   635,014               6               6,488
  Dividends paid on Series B Preferred
   Stock                                           -               -                   -
                                          ----------------------------------------------
Balance at December 31, 1997               8,912,630              89              52,762
  Net income                                       -               -                   -
  Accretion of Series A Preferred Stock            -               -                (42)
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                     180,688               2               1,362
     Exercise of warrants                    138,125               1                 994
     Conversion of debt                            -               -                   -
     Conversion of preferred stock           447,500               4               3,772
     Employee savings plan contribution        4,215               -                  41
  Dividends paid on Series B Preferred                                                  
   Stock                                           -               -                   -
                                          ----------------------------------------------

Balance at June 30, 1998                   9,683,158         $    96          $   58,889
                                          ==============================================
<CAPTION>
                                           RETAINED
                                           EARNINGS
                                           (DEFICIT)          TOTAL
                                           ---------          -----
<S>                                         <C>               <C>
Balance at December 31, 1996                 $ (12,940)       $  25,704
  Net income                                      8,092           8,092
  Issuance of Series A Preferred Stock                                
   and common stock purchase warrants                 -           3,798
  Accretion of Series A Preferred Stock               -               -
  Issuance of Series B Preferred Stock
   and common stock purchase warrants                 -          19,984
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                              -             503
     Exercise of warrants                             -           3,618
     Conversion of debt                               -           4,907
     Conversion of preferred stock                    -               -
     Employee savings plan contribution               -              35
     Business combinations                            -           6,494
  Dividends paid on Series B Preferred
   Stock                                          (395)           (395)
                                          -------------------------------
Balance at December 31, 1997                    (5,243)          72,740
  Net income                                      6,719           6,719
  Accretion of Series A Preferred Stock               -               -
  Issuance of common stock and
   common stock purchase warrants for:
     Exercise of options                              -           1,364
     Exercise of warrants                             -             995
     Conversion of debt                               -               -
     Conversion of preferred stock                    -               2
     Employee savings plan contribution               -              41
  Dividends paid on Series B Preferred
   Stock                                          (936)           (936)
                                          -------------------------------

Balance at June 30, 1998                         $  540       $  80,925
                                          ===============================
</TABLE>

                             See accompanying notes


                                       6
<PAGE>   8
                                    KTI, INC.
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
          (IN THOUSANDS OF DOLLARS EXCEPT SHARE AND PER SHARE AMOUNTS)

                                  JUNE 30, 1998

1.  BASIS OF PRESENTATION

         The accompanying unaudited consolidated financial statements have been
prepared in accordance with generally accepted accounting principles for interim
financial information and with the instructions to Form 10-Q and Article 10 of
Regulation S-X. Accordingly, they do not include all of the information and
footnotes required by generally accepted accounting principles for complete
financial statements. In the opinion of Management, all adjustments (consisting
only of normal recurring accruals) considered necessary for a fair presentation
have been included. Operating results for the three months ended June 30, 1998
are not necessarily indicative of the results that may be expected for the year
ending December 31, 1998. For further information, refer to the consolidated
financial statements and footnotes thereto included in the Company's annual
report on Form 10-K for the year ended December 31, 1997. Certain 1997 financial
information contained herein has been reclassified to conform with the 1998
presentation.

2.  EARNINGS PER SHARE

         In 1997, the Financial Accounting Standards Board issued Statement No.
128, Earnings per Share. Statement 128 replaced the calculation of primary and
fully diluted earnings per share with basic and diluted earnings per share.
Unlike primary earnings per share, the basic earnings per share excludes any
dilutive effects of options, warrants and convertible securities. Diluted
earnings per share is very similar to the previously reported fully diluted
earnings per share. All earnings per share amounts have been presented, and
where appropriate, restated to conform to the Statement 128 requirements.

         The following table sets forth the computation of basic and diluted
earnings per share:

<TABLE>
<CAPTION>
                                                         THREE MONTHS ENDED JUNE 30,      SIX MONTHS ENDED JUNE 30,
                                                             1998           1997            1998            1997
                                                        ---------------------------------------------------------------
<S>                                                     <C>                 <C>             <C>             <C>
Numerator:
   Net income                                                  $ 4,727           $ 776         $ 6,719         $ 2,135
   Preferred stock dividends                                       469               -             936               -
   Accretion of preferred stock                                      -             499              42             499
                                                        ---------------------------------------------------------------
   Numerator for basic earnings per share-net income
     available to common stockholders                            4,258             277           5,741           1,636
   Effective of dilutive securities                                469               -             936               -
     Accretion of Preferred Stock                                    -               -              42               -
                                                        ---------------------------------------------------------------

   Numerator for diluted earnings per share-net income
    available to common stockholders
    after assumed conversions                                  $ 4,727           $ 277         $ 6,719         $ 1,636
                                                        ===============================================================

Denominator:
   Denominator for basic earnings per share-weighted
    average shares                                           9,614,163       6,894,926       9,424,451       6,868,993
   Effect of dilutive securities:
    Employee stock options                                     559,010         103,432         498,330          97,147
    Warrants                                                   349,722         262,109         432,574         253,618
    Convertible preferred stock                              1,821,277               -       1,920,430               -
                                                        ---------------------------------------------------------------
   Dilutive potential common shares
    Denominator for diluted earnings per share-adjusted
     weighted-average shares and assumed conversions        12,344,172       7,260,467      12,275,785       7,219,758
                                                        ===============================================================
Net income per share-Basic                                       $0.44           $0.04           $0.61           $0.24
                                                        ===============================================================
Net income per share-Diluted                                     $0.38           $0.04           $0.55           $0.23
                                                        ===============================================================
</TABLE>


                                       7
<PAGE>   9
3.  CONTINGENCIES

         The Company is a defendant in certain law suits alleging various claims
incurred in the ordinary course of business. Management of the Company does not
believe that the outcome of these matters, individually or in the aggregate,
will have a material effect on the Company's financial condition, cash flows or
results of operations.


                                       8
<PAGE>   10
ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
         OF OPERATIONS (IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)


RESULTS OF OPERATIONS

REVENUES

         Consolidated revenue for the three months and six months ended June 30,
1998, compared with the same periods in 1997, increased $28,977 or 141.5% and
$48,011 or 122.9%, respectively. Of these increases approximately $14,937 for 
the three months and $32,802 for the six months is attributable to the recycling
division and $14,040 for the three months and $15,209 for the six months is
attributable to the waste to energy division.

         KTI's waste to energy division showed increases in electric power and
steam revenues of $12,995 and $13,900 or 121.4% and 68.8% for the quarter and
six months ended June 30, 1998 as compared to the same periods in 1997. The
increase in revenue is due primarily to the restructuring of the Power Purchase
Agreement ("PPA") with Bangor Hydro-Electric. In connection with this
restructuring, the Company received $6,000 in cash and an agreement from Bangor
Hydro-Electric to pay $250 per quarter over the next four years (total of
$4,000). PERC recorded the present value of these payments of approximately
$3,600, plus the $6,000, as revenue in the quarter. In addition, Bangor
Hydro-Electric issued warrants to purchase one million shares of Bangor
Hydro-Electric Common Stock. The Company's share, based upon its ownership
percentage at PERC, was approximately 713 thousand warrants. The estimated fair
market value of these warrants as of the date of issuance was $5.35 per warrant
and the Company recorded revenue of $3,814 in the quarter. Exclusive of this
restructuring, PERC posted a decrease in revenues of $161 or 3.3% for the
quarter because it also experienced operational problems from the heavy rains in
the area.

         Maine Energy posted an overall decrease in revenue for the quarter
ended June 30, 1998 as compared to the same period in 1997 of $622 or 13.4%;
principally from a decrease of $912 in the amortization of deferred revenue.
This was offset by both a 2.0% increase in the contract rate for power at the
facility and an increase resulting from the scheduled plant outage in April
being less extensive than the prior year, net of the reduced output due to
flooding caused by heavy rains. The rains also caused wet fuel issues.

         Timber Energy posted an increase in electric power revenue over 1997
of $192 or 16.3% because of an increase in the capacity payment from Florida
Power and from a 66.0% increase in electrical generation. Timber Energy had its
first major overhaul in the second quarter of 1997 and its electrical generator
was off-line for 6 weeks during that quarter. This increase was offset by a
$.004 per kilowatt hour reduction in the energy rate paid by Florida Power. On
June 16, 1998 KTI acquired Multitrade Group, Inc., a Virginia corporation which
currently owns and operates two facilities which incinerate biomass waste and
coal to produce steam for sale to major users under long-term contracts.
Revenue from Multitrade for the period was $217.

         Maine Energy has generated 2.5% fewer kilowatt hours for the six month
period than the prior year while receiving 2.3% higher revenues per kilowatt
hour; resulting in $11 or 0.7% higher revenues. PERC has generated 1.3% higher
kilowatt hours, but has received 0.4% less revenue per kilowatt hour for the
same period; resulting in $78 or 0.9% higher revenues. Timber Energy has
generated 20.4% higher kilowatt hours for the period but has received 10.4% less
per kilowatt hour; resulting in a $154 increase for the six months or 6.1%. Each
of the facilities have experienced operational problems because of abnormal
weather throughout the six months. Timber also experienced lower generation
because of reduced steam flow to the turbine during the first quarter of 1998,
which was attributable to superheater failures in the boiler. This problem was
repaired during the facility's scheduled outage in April, 1998.

         Revenues from waste processing increased $1,045 or 13.2% for the
quarter ended June 30, 1998 and $1,309 or 8.3% for the six months ended June
30, 1998 as compared to the same periods in 1997.


                                       9
<PAGE>   11
         Maine Energy received approximately 7.9% more tons of MSW in this
quarter than the same period in 1997, and tipping fees averaged approximately
$8.74 or 29.1% per ton more than 1997. PERC received nearly the same tonnage in
the quarter as in 1997, but tipping fees averaged $2.15 or 4.7% higher than
1997. Timber Energy's wood chip processing revenues decreased by $22 or 6.7%
principally because pulp mill customers required less tonnage during the
quarter. Timber's plastics division was sold on July 1, 1997; resulting in a
reduction of $525 in revenue for the quarter. Revenues at AAR Tennessee
decreased $124 or 26.6% because less tonnage was processed. Effective June 1,
1998 all KTI Specialty Waste tonnage was transferred to Total Waste Management,
which was acquired January 27, 1998. This transfer was part of KTI's long range
plan to integrate the two waste streams into a company that can provide more
complete disposal services over a wider array of waste streams which would
command higher tipping fees. Total Waste Management posted increased revenues of
$860 for the quarter over KTI Specialty Waste and SEMCO for the same period last
year.

         Through June 30, 1998, the combined waste processing revenue at Maine
Energy and PERC was $9,887 or 10.0% higher than the same period in 1997 because
tonnage received was 5.1% higher and average tipping fees were higher. The
success in moving tipping fees higher during the second quarter has resulted in
tipping fees for the six months ending June 30, 1998 being 4.8% higher than the
same period in 1997.

         Recycling revenue increased $14,937 in the second quarter and $32,802
for six months of 1998, as compared to the same periods in 1997. This increase
is principally a result of the acquisitions of Zaitlin, K-C International and
the assets of the Prins facilities during the third and fourth quarter of 1997.
Recycling revenues are generated from the sales of waste paper, ferrous and
non-ferrous materials, and plastic materials.

COSTS AND EXPENSES

         Electric power and waste handling operating costs increased by $4,635
or 41.2% for the quarter ended June 30, 1998 and $4,894 or 22.5% for the six
months ended June 30, 1998 as compared to the same periods in 1997. PERC's
operating costs were $3,907 higher as a result of additional contractual
payments to municipalities and its electric power customer generated by the
income from the restructuring of the PPA. Exclusive of this item, the costs of
operating PERC were higher by $306 or 8.0% for the quarter because of scheduled
maintenance costs.

         Operating costs of the new divisions of Total Waste Management and
Power Ship were $948 and $904 for the quarter and $1,440 and $1,322 for the six
months respectively. Maine Energy's operating costs were lower by $142 or 3.5%
for the quarter and $248 or 3.7% for the six months principally because of
reduced maintenance costs at the facility.

         Operating costs at Timber Energy are lower by $490 or 36.8% and $944 or
34.2% for the quarter and six months due to the sale of the plastics division
and overall lower maintenance costs. Operating costs at Multitrade were $63
since its acquisition on June 16, 1998.

         General and administrative expenses increased by $913 or 81.7% for the
three months and $950 or 43.9% for the six months ended June 30, 1998 as
compared to 1997. During the second quarter of 1998 the Company added
administrative staff to develop and install Company wide computer networks; to
support Company wide credit and collection efforts; to identify and pursue
potential mergers and acquisitions; and to develop internal analytical systems
to identify revenue enhancement and cost savings programs in newly acquired
entities.

INTEREST

         Interest expense increased $225 or 17.0% for the three months and $735
or 31.6% for the six months ended June 30, 1998 as compared to the same periods
in 1997. Interest expense at Timber Energy increased $128 or 53.9% due to the
restructuring of the variable rate bonds to fixed coupon rates during the second
quarter of 1997. Reductions in interest expense of $335 were realized through
debt reductions at most of KTI's operating facilities, which were offset by
increases related to increased borrowings on the Company's line of credit to
fund acquisitions beginning in the third quarter of 1997.


                                       10
<PAGE>   12
INCOME TAX PROVISION

         The income tax provision was $3,347 in the quarter and $4,693 for the
six months. The primary difference in the income tax provision at the federal
statutory rate and the recorded amounts for the periods indicated is due to
state income tax provision and the impact of nondeductible goodwill from stock
acquisitions.

EXTRAORDINARY LOSS ON EARLY RETIREMENT OF DEBT

         The Company recorded an extraordinary loss on early retirement of the
PERC bonds for the quarter and six months of $495. This amount is net of
minority interest and income tax benefits.

LIQUIDITY AND CAPITAL RESOURCES

         The Company is a holding company and receives cash flow from its
subsidiaries. Receipt of cash flow from PERC is currently restricted by
covenants under loan agreements, distribution restrictions under partnership
agreements with its equity investors, and put-or-pay agreements with
municipalities. Maine Energy's cash flow is required to retire the remaining
outstanding balance of $14,105 of subordinated notes payable as of June 30, 1998
(approximately $2,495 of which notes are owned by the Company) before cash
distributions to partners can begin. Timber Energy's cash flow is restricted by
covenants under its bond agreements. As a result, the following discussion is
organized to present liquidity and capital resources of the Company separate
from Maine Energy, PERC and Timber and liquidity and capital resources of each
of Maine Energy, PERC and Timber independently.

  THE COMPANY

         The Company has financed its operations and capital expenditures
primarily from cash flow from its subsidiaries which are not contractually
restricted from making distributions, management fees and allowed distributions
from contractually restricted subsidiaries, collateralized equipment financing,
proceeds from the sale of the Company's common and preferred stock and drawings
under its lines of credit.

         On June 4, 1997, the Company consummated the private placement of
487,500 shares of its Series A Convertible Preferred Stock for gross proceeds of
$3,900 and net proceeds of $3,798. The Series A Convertible Preferred Stock was
convertible into shares of the Company's Common Stock, at a price of $8.00 per
share, subject to adjustment. Purchasers of the shares of Series A Convertible
Preferred Stock also received, in the aggregate, warrants to purchase 243,750
shares of Common Stock at $9.00 per share and warrants to purchase 32,500 shares
of Common Stock at $10.00 per share. During 1997, 40,000 of the shares of Series
A Convertible Preferred Stock were converted to 40,000 shares of Common Stock.
The remaining shares of Series A Convertible Preferred Stock were converted into
447,500 shares of Common Stock in February 1998.

         On June 5, 1998 the Company exercised its option to exchange all of the
outstanding shares of the Series B Preferred Stock for KTI's 8.75% Convertible
Subordinated Notes. The exchange will be effective August 3, 1998. The holders
of outstanding shares of Series B Preferred are entitled to receive a $1
principal amount exchange note for each 40 shares of Series B Preferred held.
KTI will pay $25.00 per share for the portion of any holder's position that is
less than 40 shares. Dividends on Series B Preferred will cease August 3, 1998
whether or not the certificates for shares have been surrendered.

         The Company and its subsidiaries, other than Maine Energy, PERC and
Timber Energy at June 30, 1998 had indebtedness maturing in the next year of
$4,759. During the first six months of 1998, the Company, other than Maine
Energy, PERC and Timber Energy incurred additional debt (including net
borrowings on lines of credit) of approximately $20,599, primarily as a result
of drawings under its lines of credit for acquisitions; and retired
approximately $2,558 of debt.

         As of June 30, 1998, the Company had cash on hand without regard to
Maine Energy, PERC and Timber Energy of approximately $897, plus $5,878
available in lines of credit from a bank. On May 28,


                                       11
<PAGE>   13
1998, KeyBank increased its credit line from $22 million to $30 million as part
of its commitment to provide KTI with an increase in the overall acquisition
credit line to $150 million. On July 13, 1998 KeyBank and KTI closed on the $150
million acquisition credit line. This line of credit can be utilized to fund
acquisitions, capital expenditures and for working capital. There can be no
assurance such acquisitions or capital expenditures will take place, or that
working capital will be increased. Management of the Company believes that cash
flow from its subsidiaries and affiliates and unused lines of credit will meet
its current needs for liquidity. Moreover, management believes that the Company
has the ability to access additional borrowing facilities if needed, although no
assurance can be given in this regard.


  MAINE ENERGY

         Maine Energy has financed its operations and capital expenditures from
cash flows from operations. Cash provided by (used in) operations was $1,170 and
($544) for the six months ended June 30, 1998 and 1997, respectively. As of June
30, 1998, Maine Energy had total indebtedness of $14,105. Maine Energy's capital
expenditures for property, plant, and equipment were $1,678 and $522 for the six
months ended June 30, 1998 and 1997, respectively.

         As of June 30, 1998, in addition to Maine Energy's operating cash of
$1,807, Maine Energy, as required under the terms of the credit agreement with
its letter of credit, has on account an additional $6,081 of reserves to be used
for capital improvements, debt service, operating shortfalls and working capital
requirements.

         Management of the Company believes Maine Energy has adequate cash
resources available to fund its future operations and anticipated capital
expenditures. Capital expenditures for Maine Energy for the year ending December
31, 1998 are expected to be approximately $3,043, of which $1,850 has been set
aside in the above mentioned reserve accounts.

  PERC

         PERC has financed its operations and capital expenditures primarily
from cash flows from operations. Cash provided by operations was $9,882 and
$5,515 for the six months ended June 30, 1998 and 1997, respectively. PERC's
capital expenditures were $164 and $93 for additions to property, plant and
equipment during the six months ended June 30, 1998 and 1997, respectively.

         On June 26, 1998 KTI completed a major overhaul of the various
contracts and obligations of PERC, which included refinancing PERC's tax exempt
bonds. The refinancing was made possible through the sale of $45,000 in Electric
Rate Stabilization Revenue Refunding Bonds issued by the Finance Authority of
Maine ("FAME"). The interest rate on the bonds ranges from 3.75% for one-year
bonds to 5.20% for 20-year term bonds. This transaction will reduce PERC's debt
service costs while extending its payment obligation over 20 years.

         As of June 30, 1998, in addition to PERC's operating cash of $6,816,
PERC, as required under the terms of the trust indenture governing the FAME
Bonds, had on account an additional $11,700 of cash reserves to be used for
capital improvements, debt service, operating shortfalls and working capital
requirements.

         Company management believes PERC has adequate cash resources available
to fund its current project operations and currently anticipated capital
expenditures. PERC plans capital expenditures for the year ending December 31,
1998 of approximately $765. PERC intends to finance this amount through cash
flow from operations.

  TIMBER ENERGY

         As of June 30, 1998, Timber Energy had outstanding tax exempt bonds,
together with accrued interest, in the aggregate amount of $13,400. The bonds
are payable pursuant to a mandatory redemption schedule through December 1,
2002.


                                       12
<PAGE>   14
         As of June 30, 1998, in addition to Timber Energy's operating cash of
$507, Timber Energy, as required by the terms of the refinancing, had an
additional $3,314 of cash reserves to be used for debt service.

         Company management believes Timber Energy has adequate cash resources
available and expects additional cash from operations to fund its current
operations and debt obligations. Timber Energy plans capital expenditures in
1998 of approximately $526, which will be funded from cash provided by
operations.

SUBSEQUENT EVENTS

         On June 29, 1998, the Company announced that it signed letters of
intent to acquire Gaccione Bros. of Clifton, New Jersey and Atlantic Coast
Fibers of Passaic, New Jersey. The two companies will be brought together to
create one of the largest high-grade paper processing facilities in the country.
The annual combined revenue of the two companies is approximately $20 million.

         On August 5, 1998, the Company announced that it has reached a
definitive agreement to acquire all of the outstanding stock of FCR, Inc, a
Delaware corporation ("FCR"), having its headquarters in Charlotte, North
Carolina. The purchase price consists of: (a) 1,714,285 shares of the Company's
common stock; (b) $30.0 million in cash; and (c) an earnout of up to $30.0
million to be paid in cash and stock. The number of shares earned will be
calculated at the higher of $23 per share or the then market value of such
shares, based on the average of closing sale price per share during the ten
trading days preceding the payment date.

         The merger is contingent upon compliance with the Hart Scott Rodino
Antitrust Improvement Act and other customary conditions.

         FCR is a national waste processing company, owning 26 plants in 12
states. The plants operate in three businesses; material recovery facilities,
cellulose insulation and plastic recycling.

         Eighteen of the plants are material recovery facilities, based in 10
states. These plants currently process materials at the rate of 650,000 tons of
recyclables per year.

         Five of the plants are cellulose insulation plants, based in four
states. A sixth cellulose insulation plant is under construction. The cellulose
insulation plants operate under the name of U.S. Fiber, Inc.

         The plastic recycling business operates three plastic recycling plants.
These plants currently process plastic at the rate of 50 million pounds per
year. The Company has a subsidiary in the plastic trading and brokerage
business, which presently trades plastic at the rate of 40 million pounds per
year.

         In August 1998, substantially all of the warrants issued in 
conjunction with Series A Convertible Preferred Stock were exercised in 
exchange for 160,677 shares of the Company's common stock.

         On August 5, 1998 the Company acquired First State Recycling, Inc., a
Delaware corporation headquartered in Wilmington, Delaware, for $1.9 million in
cash and KTI common stock. As a processor of plastics for resale, First State
generated gross revenues of $2 million in 1997 and is expected to reach $4
million in 1998.


                                       13
<PAGE>   15
FORWARD LOOKING STATEMENTS

         All statements contained herein which are not historical facts
including but not limited to statements regarding the Company's plans for future
cash flow and its uses are based on current expectations. These statements are
forward-looking in nature and involve a number of risks and uncertainties.
Actual results may differ materially. Among the factors that could cause actual
results to vary materially is the availability of sufficient capital to finance
the Company's business plan and other capital needs on terms satisfactory to the
Company. The Company wishes to caution readers not to place undue reliance on
any such forward looking statements, which statements are made pursuant to the
Private Litigation Reform Act of 1995 and as such speak only as of the date
made.


                                       14
<PAGE>   16
PART II - OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS


     Maine Energy is the plaintiff in a suit in the State of Maine against
United Steel Structures, Inc. under a warranty to recover the costs, which were,
or will be incurred to replace the roof and walls of the Maine Energy tipping
and processing buildings. The judge in the case entered an order awarding Maine
Energy $3,334 plus interest from May 10, 1994, to the date of the filing of the
lawsuit and court costs. The defendant filed an appeal on December 19, 1997.
There can be no assurance that the Company will be able to collect any amount of
this judgement.

     Lawsuits were filed on September 30, 1997 and March 6, 1998 by Capital
Recycling of Connecticut ("Capital") in a Connecticut State Court against K-C,
certain officers of K-C and other parties. The suits allege fraud, tortuous
interference with business expectancy and violations of the Connecticut Unfair
Trade Practices Act. The actions are based on two contracts between Capital and
K-C. The lawsuit was dismissed with prejudice as to the officers of K-C and all
claims between the parties are to be resolved in the arbitration proceedings.
The Company believes that it has meritorious defenses to the arbitration
proceedings.

     The Company is a defendant in certain other law suits alleging various
claims incurred in the ordinary course of business, none of which, either
individually or in the aggregate, the Company believes will have a material
adverse effect on the Company.

     Management of the Company does not believe that the outcome of the
foregoing matters, individually or in the aggregate, will have a materially
adverse effect on the Company's financial condition, cash flows or results of
operations.

ITEM 2.  CHANGES IN SECURITIES

         Not applicable.

ITEM 3.  DEFAULTS UPON SENIOR SECURITIES

         Not applicable.

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         Not applicable

ITEM 5.  OTHER INFORMATION

         Not applicable


                                       15
<PAGE>   17
ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

         (a)      Exhibits

                  None

         (b)      Reports on Form 8-K

                  Six reports on Form 8-K were filed in the second quarter of
1998. The following is a list of the Forms 8-K filed and the dates thereof.

                  (i) A Form 8-K was filed on May 7, 1998 reporting that the
Company signed a letter of intent to acquire FCR, Inc., a Delaware corporation.

                  (ii) A Form 8-K was field on June 17, 1998 announcing the
conversion of the Company's Series B Preferred Stock to 8.75% Convertible
Subordinated Debt effective August 3, 1998.

                  (iii) A Form 8-K was filed on June 25, 1998 announcing the
acquisition of Multitrade Group, Inc., a Virginia corporation.

                  (iv) A Form 8-K was filed on July 8, 1998 reporting that the
Company completed the refinancing of the existing tax exempt bonds issued by the
Town of Orrington, Maine to finance the construction of the facility owned by
PERC.

                  (v) A Form 8-K was filed on July 15, 1998 announcing the
signing of a $150 million acquisition line of credit with KeyBank.

                  (vi) A Form 8-K was filed on August 5, 1998 announcing the
purchase of substantially all of the assets of First State Recycling, Inc. for
cash and stock in the amount of $1.85 million. The Company is purchasing First
State Recycling subject to existing funded debt of $445,000.



                                       16
<PAGE>   18
                                   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.


                              KTI, Inc.
                              (Registrant)




                              By: /s/  Ross Pirasteh
                                   Name:    Ross Pirasteh
                                   Title:   Chairman of the Board of Directors



                              By: /s/  Martin J. Sergi
                                    Name:   Martin J. Sergi
                                    Title:  President and Chief
                                            Financial Officer
                                            (Principal Accounting Officer)




Date: August 13, 1998


                                       17