Report on Exercise of STEC-W No.9/2005

Ref: ST/010/2005/0042 April 1st, 2005 Re: Report on the Exercise of Warrants No.9/2005 To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to report the exercise of warrants (STEC-W) No.9 on March 30th, 2005 as per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share - Exercising price: Baht 1 per share - Ordinary shares reserved to support the exercise: 4,236,650 shares - No. of warrant holders exercise: 6 - No. of warrants being exercised at No.9/2005: 1,957,800 units - Ordinary shares resulted from the exercise at No.9/2005: 1,957,800 shares - Money received from the exercise at No.9/2005: Baht 1,957,800 - Total remaining warrants listed in the Stock Exchange of Thailand: 2,278,850 units Please be informed accordingly. Yours sincerely, Ms. Anilrat Nitisaroj Vice President - Investor Relations