Italian construction group Webuild announced Tuesday it had signed a $16-billion contract to build a high-speed railway line between Dallas and Houston in the US state of Texas. "The agreement is the final step ahead of the financial closure -- foreseen in the coming months -- and the start of construction of the mega project, which will provide fast, safe and environmentally friendly travel, create thousands of jobs and give a major boost to the economy," said the group, formerly known as Salini Impregilo. bh-ar/lth