Citigroup and Barclays will reportedly settle a lawsuit with private investors who say the banks manipulated foreign-exchange rates within the week.The Banks are expected to pay up to a combined $800m to settle the lawsuit, considerably larger payments than those made by JP Morgan and UBS who have settled their parts of the same lawsuit.The settlement would be the latest development in the global investigation against big banks over their alleged rigging of currencies markets.The Justice Department previously encouraged Citigroup and Barclays to plead guilty to criminal antitrust charges against plaintiffs such as pension funds and other investment firms.