The parent companies or main banking units of as many as five major banks, rather than their smaller subsidiaries, are expected to plead guilty to U.S. criminal charges over manipulation of foreign exchange rates, people familiar with the matter said. A handful of banks will likely resolve forex-rigging investigations by the U.S. Justice Department as soon as this week: JPMorgan Chase & Co (JPM.N) Citigroup (C.N), British banks Royal Bank of Scotland (RBS.L) and Barclays (BARC.L) and Swiss bank UBS (UBSG.VX).