Report on the Exercise of Warrants (STEC-W, STEC-W2)

Ref: ST/010/2005/0081 October 4th, 2005 Re: Report on the Exercise of Warrants (STEC-W No.11/2005, STEC-W2 No.2/2005) To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to report the exercise of STEC-W No.11 and STEC-W2 No.2 on September 30th, 2005 as per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share - Exercising price of STEC-W : Baht 1 per share - Exercising price of STEC-W2 : Baht 8.50 per share - Ordinary shares reserved to support the exercise of STEC-W: 2,188,650 shares, and STEC-W2: 164,635,393 shares - No.of STEC-W holders exercise: 3 , STEC-W2 holders exercise: 4 - No.of warrants being exercised at No.11/2005: 299,700 units, and No. 2/2005: 1,006,932 units - Ordinary shares resulted from the exercise at No.11/2005: 299,700 shares, and No.2/2005: 1,006,932 shares - Money received from the exercise at No.11/2005: 299,700 Baht, and No.2/2005: 8,558,922 Baht - Total remaining warrants listed in the Stock Exchange of Thailand No.11/2005:1,888,950 units, and No. 2/2005: 163,628,461 units Please be informed accordingly. Yours sincerely, Ms. Anilrat Nitisaroj Vice President - Investor Relations