Canadian engineering giant WSP Global Inc. is buying John Wood Group PLC’s environment business in a deal that cements its position as one of the world’s dominant players in sustainable development consulting. Montreal-based WSP said Wednesday it struck a definitive agreement to take over a business known as Environment & Infrastructure (E&I) from Aberdeen, Scotland-based Wood for US$1.8-billion, including a US$200-million deal-related tax benefit. The agreement adds 6,000 employees to WSP’s payroll from about 55,000 currently and sharpens its ability to bid on major environmental and infrastructure projects, particularly for federal government departments in the United States.