<PAGE>   1
EXHIBIT 99
                 AGREEMENT REGARDING PURCHASE PRICE ADJUSTMENTS

         THIS AGREEMENT REGARDING PURCHASE PRICE ADJUSTMENTS ("AGREEMENT") is
entered into this 24th day of September 1998 by and among Edac Technologies
Corporation, a Wisconsin corporation ("EDAC"); Apex Machine Tool Company, Inc.,
a Connecticut corporation and a wholly owned subsidiary of Edac which was
formerly known as Apex Acquisition Corporation ("BUYER"); the Biondi Tool
Company, Inc., a Connecticut corporation which was formerly known as Apex
Machine Tool Company, Inc. ("SELLER"); and Gerald S. Biondi, James G. Biondi and
Michael Biondi (collectively, the "SHAREHOLDERS").

                                    RECITALS:

         A. Edac, Apex Acquisition Corporation, a Wisconsin corporation ("APEX
ACQUISITION"), Seller and the Shareholders are parties to that certain Asset
Purchase Agreement, dated as of May 13, 1998 (the "ASSET PURCHASE AGREEMENT"),
providing for the purchase and sale of substantially all of the assets and
liabilities of Seller.

         B. Prior to the closing of the transactions contemplated by the Asset
Purchase Agreement (the "Closing"), Apex Acquisition assigned to Buyer all of
its rights and obligations under the Asset Purchase Agreement.

         C. The Closing took place on June 30, 1998.

         D. Section 3.3 of the Asset Purchase Agreement generally provides that
the Purchase Price for the Purchased Assets shall be adjusted upward or downward
to the extent of any increase or decrease, respectively, in the Adjusted Net
Asset Value of Seller as of the Closing Date from the Adjusted Net Asset Value
of Seller as of November 30, 1997.

         E. The parties have reached an agreement concerning the nature and
extent of the adjustments to the Purchase Price contemplated by Section 3.3 of
the Asset Purchase Agreement.

         F. All capitalized terms used in this Agreement that are not otherwise
defined herein shall have the meanings that have been ascribed to them in the
Asset Purchase Agreement

         NOW, THEREFORE, in consideration of the foregoing, of the mutual
covenants and agreements herein contained and of other good and valuable
consideration, the receipt, adequacy and sufficiency of which are hereby
acknowledged, the parties hereto hereby agree as follows:

         1. PURCHASE PRICE ADJUSTMENT. Each of the undersigned parties to this
Agreement hereby irrevocably agrees to the adjustments to the Purchase Price set
forth on the adjustment sheet attached as EXHIBIT A hereto (the "ADJUSTMENT
SHEET"). Without limiting the generality of the foregoing, each of the
undersigned parties to this Agreement hereby irrevocably agrees that the net
amount of the over-all adjustment to the Purchase Price (the "PURCHASE PRICE
ADJUSTMENT") is a reduction in the aggregate amount of Two Hundred Sixty-Two
Thousand Two Hundred Thirty-One Dollars ($262,231.00). Seller hereby agrees to
pay the full amount of the Purchase Price Adjustment to Buyer within five
business days of the date of this Agreement.

         2. NO FURTHER ADJUSTMENTS. The adjustments reflected on the Adjustment
Sheet represent a negotiated settlement and constitute the parties' final
agreement concerning the adjustments to the Purchase Price contemplated by
Section 3.3 of the Asset Purchase Agreement. Each of the undersigned parties
hereby irrevocably waives any right it has, or may have at, law or in equity, to
require any further adjustment to the Purchase Price; provided, however, that
except as set forth in Section 3 hereof, nothing in this Agreement shall be
deemed to impair or affect the right of any party to make a claim for
indemnification under the applicable provisions of the Asset Purchase Agreement.

         3. INDEMNIFICATION OBLIGATIONS UNAFFECTED. None of the adjustments
reflected on the Adjustment Sheet shall be deemed to constitute a breach or
violation of any of the representations or warranties of Seller and/or the
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Shareholders set forth in the Asset Purchase Agreement. Accordingly, none of
such adjustments shall be deemed to constitute a Loss for purposes of the
indemnification obligations of Seller and/or the Shareholders set forth in
Article X of the Asset Purchase Agreement; nor shall any such adjustments be
included in the calculation of Losses for purposes of Section 10.5 of the Asset
Purchase Agreement. To the extent that the Adjustment Sheet refers to any
specific adjustments that are being split or apportioned among the parties, each
of the undersigned parties to this Agreement hereby irrevocably agrees that the
total amount of any such adjustments (and not just the amount reflected on the
Adjustment Sheet) shall not be deemed to constitute a Loss for purposes of the
indemnification obligations of Seller and/or the Shareholders set forth in
Article X of the Asset Purchase Agreement; nor shall the total amount of any
such adjustments be included in the calculation of Losses for purposes of
Section 10.5 of the Asset Purchase Agreement.

         4. PRONOUNS AND HEADINGS. As used herein, all pronouns shall include
the masculine, feminine, neuter, singular and plural wherever the context and
facts require such construction. The descriptive headings in the sections of
this Agreement are inserted for convenience of reference only and shall not
control or affect the meaning or construction of any of the provisions hereof.

         5. GOVERNING LAW. This Agreement shall be governed by and construed in
accordance with the laws of the State of Connecticut, without regard to the
conflict of laws provisions thereof.

         6. BINDING EFFECT; COMPLETE AGREEMENT. This Agreement shall be binding
upon and shall inure to the benefit of the parties hereto and their respective
heirs, personal representatives, successors and assigns. This Agreement
constitutes the entire agreement among the parties hereto and supersedes all
prior agreements and understandings, oral or written, among the parties hereto
with respect to the subject matter hereof.

         7. COUNTERPARTS.  This Agreement may be executed in one or more 
counterparts,  each of which shall be deemed an original, and all of which 
together shall constitute one and the same instrument.

              [Remainder of this page is intentionally left blank.]
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         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
day and year first above written.


                                  EDAC TECHNOLOGIES CORPORATION


                                  By:    /s/ Edward J. McNerney 
                                         ---------------------------------
                                         Name: Edward J. McNerney
                                         Title: President & CEO


                                  APEX MACHINE TOOL COMPANY, INC.


                                  By:    /s/ Edward McNerney
                                         ---------------------------------
                                         Name: Edward McNerney
                                         Title: CEO


                                  BIONDI TOOL COMPANY, INC.


                                  By:    /s/ Gerald S. Biondi
                                         ---------------------------------
                                         Name: Gerald S. Biondi
                                         Title: President


                                  /s/ Gerald S. Biondi
                                  ----------------------------------------
                                  Gerald S. Biondi


                                  /s/ James G. Biondi
                                  ----------------------------------------
                                  James G. Biondi


                                  /s/ Michael Biondi
                                  ----------------------------------------
                                  Michael Biondi

                                      -3-
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                                  APEX MACHINE
                               CLOSING ADJUSTMENT
                                      FINAL

<TABLE>
<CAPTION>

<S>                                                                         <C>      
Total assets per AA statements (net of cash and leasehold improve)          7,059,050
Total current liabilities per AA statements (net of grant income)           1,894,084
                                                                            ---------
Adjusted book value per AA                                                  5,164,966

Accounts receivable adjustment                                                 60,000
Accounts receivable insurance company                                          54,263
Inventory adjustment per Tom's calculation ($1,451,081)                       -22,212
Rework job treated inconsistently with November 30                              2,804
Design training hours treated inconsistently with November 30                  24,224
Design jobs #1239 treated inconsistently with November 30                       4,416
Design job canceled, but subsequently billed                                    2,964
Nypro completed /unbilled job omitted from inventory                            4,690
Correct depreciation calculation                                                9,843
50% of cost of software                                                       -79,613
Accounts payable cut-off                                                       11,718
Kistler invoice-credits not applied to balance                                  2,840
Accrued SUTA-not done at November 30                                           36,922
Unapplied cash account-amount duplicated                                        7,418
Adjust accrued vacation to be consistent with November 30                     141,842
50% legal fee for deferred grant income                                        -1,267
Bonuses & profit sharing                                                     -193,937
Depreciation after March 31                                                   133,916
Additional 1.5 months insurance reserve to be consistent with November 30      91,823
                                                                            ---------
                                                                            5,457,620
                                                                            ---------

Adjusted book value as of November 30                                       5,719,851
                                                                            ---------

Net difference                                                               -262,231
                                                                            ---------
</TABLE>

REFLECTS ALL ADJUSTMENTS DISCUSSED AT MEETING OF SEPT 15