Report on the Exercise of Warrants (STEC-W2 No.9/2007)

Ref: ST/010/2007/0044 July 3rd , 2007 Re: Report on the Exercise of Warrants (STEC-W2 No.9/2007) To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to report the exercise of STEC-W2 No.9 on July 2nd , 2007 as per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share - Exercising price of STEC-W2 : Baht 8.50 per share - Ordinary shares reserved to support the exercise of STEC-W2: 163,548,461 shares - None of STEC-W2 holders exercise the warrants. - Total remaining warrants listed in the Stock Exchange of Thailand of STEC-W2 : 163,548,461 units Please be informed accordingly. Yours sincerely, Mr. Woraphant Chontong SEVP. Financial and Administration Division