FORM 6-K SECURITIES & EXCHANGE COMMISSION Washington, D.C. 20549 Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 August 27, 2003 INFICON Holding AG INFICON Holdings Inc. (Translation of registrant's name into English) INFICON Inc. Two Technology Place East Syracuse, New York 13057 (Address of principal executive offices) Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. Form 20-F |X| Form 40-F |_| Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes |_| No |X| Exhibit: 99.1 Press Release dated August 27, 2003 regarding disclosure of equity participations pursuant to the Swiss Stock Exchange Act. 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. Date: August 27, 2003 INFICON Holding AG By: /s/ Peter G. Maier ------------------------------------- Name: Peter G. Maier Title: Vice President and Chief Financial Officer 2