Tata Steel signed an agreement with Thailand-based Cementhai Holding Company, a Siam Cement group company, today to acquire approximately 40% stake in Millennium Steel and purchase an additional stake of 24.9%.According to a release issued by Tata Steel to the BSE today, the company will also make an open offer subject to certain conditions."100% equity value of Millennium Steel Company, as ascertained for the transaction, is approximately $175 million," the release added.