Royal Bank of Scotland (RBS) has settled a copyright lawsuit in the US over its use of an important piece of software in its trade finance business, the lender said on Wednesday.RBS will be allowed to use Complex Systems' Bank Trade software and continue processing trade finance transactions across all of its legal entities following the settlement. "Our clients remain our primary focus, and this settlement assures them of our continued commitment to our trade finance business," RBS said in a statement.In May, US District Judge Katherine Forrest in Manhattan entered a permanent injunction requiring RBS's ABN Amro unit to stop using the software within a year due to alleged copyright infringement. The bank was also ordered against using it to process new trade finance transactions received within 60 days from her decision.ABN, which is now called Royal Bank of Scotland NV, had stressed in court that the system was a core feature of its technical platform.The lawsuit was filed in 2008, a year after ABN Amro's $21bn sale to Bank of America Corp of LaSalle Bank and a unit that had been licensing Bank Trade from Complex Systems.Forrest argued the licence went to Bank of America but RBS continued to use the software. In March 2013, the judge ruled that ABN Amro was improperly using the BankTrade software of Complex Systems. The bank appealed the decision but the 2nd US Circuit Court of Appeals in New York denied the request on 26 June.RD