Wilbur Ross, chairman and chief executive officer of WL Ross & Co REUTERS/Brendan McDermid (UNITED STATES)   By Paritosh Bansal and Megan Davies
   NEW YORK, Aug 25 (Reuters) – U.S. regulators are likely to back down from the tough stance they took a month ago on rules for auctions of troubled banks, which could clear the way for more private equity bidders to come back into the game.