Six consortia, including more than 60 companies, have expressed their interest in building Australia' s longest rail tunnels, Sydney's North West Rail Link, New South Wales (NSW) Transport Minister Gladys Berejiklian said Tuesday. Expressions of interest have come from across Australia as well as Spain, the United States, France, the UK, South Africa, China, Italy and Japan. The NSW Government will officially call for tenders in October, with a contract to be awarded in the second half of 2013 and tunneling slated to begin in 2014, according to the Australian Associated Press (AAP) reports. The twin 15.5-kilometer tunnels between Bella Vista and Epping in Sydney's northwest will become Australia's longest rail tunnels. "The twin tunnels ... will be the longest and deepest rail tunnels in Australia," Berejiklian said in a statement. Contracts will also be awarded for surface construction and rail systems, trains and operations. The bidding process for those contracts will begin later in 2012.