South Korean steel giant POSCO and a private investor have agreed to back a plan by China's Baosteel and Aurizon Holdings Ltd to build rail lines and a port for a long-delayed $6.8 billion Australian iron ore project. POSCO and investor American Metals & Coal International (AMCI) are 50 percent owners of the West Pilbara Iron Ore project. Baosteel and Aurizon recently took over the other 50 percent following their A$1.4 billion takeover of Aquila Resources. The companies said on Thursday they had signed an infrastructure agreement, clearing one hurdle for plans to build a rail and port to handle at least 40 million tonnes of iron ore a year, with exports to start in 2017/2018. "POSCO considers the delivery of rail and port infrastructure is a key component of facilitating the development of the Pilbara project," POSCO senior vice president Kimok Yun said in a statement. (Reuters)