<PAGE>
================================================================================
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
---------------
SCHEDULE 13D/A
(AMENDMENT NO. 1)
UNDER THE SECURITIES EXCHANGE ACT OF 1934
---------------
SYNTHETIC INDUSTRIES, INC.
(Name of Issuer)
Common Stock, $1.00 par value per share
(Title of Class of Securities)
871914107
(CUSIP Number)
E. Michael Greaney, Esq.
Gibson, Dunn & Crutcher LLP
200 Park Avenue
New York, New York 10166
(212) 351-4000
(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)
November 5, 1999
(Date of Event Which Requires Filing of Statement on Schedule 13D)
================================================================================
<PAGE>
This Amendment No. 1 amends the Statement on Schedule 13D (as amended,
this "Statement") initially filed on November 15, 1999 on behalf of Sipco
Limited, a Cayman Islands corporation ("Sipco"), Investcorp S.A., a Luxembourg
corporation ("Investcorp"), SIND Holdings, Inc., a Delaware corporation
("Parent"), and SIND Acquisition, Inc., a Delaware corporation ("Purchaser"), to
report Sipco's, Investcorp's, Parent's and Purchaser's acquisition of beneficial
ownership in excess of 5% of the common stock of Synthetic Industries, Inc. (the
"Company") as a result of Parent and Purchaser entering into a Stockholder
Agreement with Synthetic Industries, L.P. (the "Stockholder") on November 5,
1999. In connection with the Stockholder Agreement, Purchaser has commenced an
offer to purchase all outstanding shares of the Company's common stock
(collectively, the "Shares") at a price of $33.00 per Share, net to the seller
in cash, without interest thereon, upon the terms and subject to the conditions
set forth in the Offer to Purchase, dated November 12, 1999 (the "Offer to
Purchase"), and the related Letter of Transmittal (which, together with any
amendments or supplements thereto, collectively constitute the "Offer").
Item 7. Material to be Filed as Exhibits
Item 7 is hereby amended by adding the following exhibit:
(g) Revolving Credit Facility Commitment Letter, dated
November 2, 1999, among Bear Stearns Corporate
Lending Inc., Bear, Stearns & Co. Inc., The Chase
Manhattan Bank, Chase Securities Inc. and Investcorp
Investment Equity Limited, and Assignment of
Commitment, dated November 16, 1999, to Fleet
National Bank (incorporated by reference to the
Schedule 14D-1 filed by Purchaser, Parent and
Investcorp on November 12, 1999, as amended)
2
<PAGE>
SIGNATURES
After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
SIND ACQUISITION, INC.
By: /s/ Christopher J. O'Brien
---------------------------------
Name: Christopher J. O'Brien
Title: President
Dated: December 6, 1999
After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
SIND HOLDINGS, INC.
By: /s/ Christopher J. O'Brien
---------------------------------
Name: Christopher J. O'Brien
Title: President
Dated: December 6, 1999
After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
INVESTCORP S.A.
By: /s/ Lawrence B. Kessler
---------------------------------
Name: Lawrence B. Kessler
Title: Authorized Representative
Dated: December 6, 1999
After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
SIPCO LIMITED
By: /s/ Gary S. Long
---------------------------------
Name: Gary S. Long
Title: Director
Dated: December 6, 1999
3