Sign BMA Office Center Contract No. 2,4,5

ST. 010/2006/0040 May 15th, 2006 Subject: Contract Signing of the Construction of Bangkok Government Office Center (Contract No.2,4,5) Attention: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited is pleased to inform the SET that on May 15th, 2006, the company has signed 3 new contracts which have details as follow: 1. Project name : Building A, Parking Building A and Parking Lot A (2nd Contract) Project owner : Dhanarak Assets Development Co.,Ltd. Contract value: THB 3,395,000,000 (Incl. VAT) Scope of work: the construction of 9 stories Build A, 2 stories Parking Building, Park Lot A, Infrastructure & related works. Construction period : 790 days 2. Project name : Parking Building B, Dormitory Building, Cubic Auditorium Building (4th Contract) Project owner : Dhanarak Assets Development Co.,Ltd. Contract value: THB 1,860,000,000 (Incl.VAT) Scope of work: the construction of 5 stories Building B, 10 stories Dormitory Building, Parking (Reflecting Pool) in North, 5 stories Cubic Auditorium Building and related works. Construction period : 790 days 3. Project name : Civil & Infrastructure System and Control Building (5thContract) Project owner : Dhanarak Assets Development Co.,Ltd. Contract value: THB 1,100,000,000 (Incl. VAT) Scope of work: the construction of Infrastructure, Control Building, and related works Construction period : 830 days It is therefore informed for your acknowledgement and dissemination to the public and other investors. Yours sincerely Mr. Woraphant Chontong SEVP. Financial and Administration Division