A new leak of confidential documents expands the list of big companies seeking secret tax deals in Luxembourg, exposing tax-saving maneuvers by American entertainment icon The Walt Disney Co., politically controversial Koch Industries Inc. and 33 other companies. Disney and Koch Industries, a U.S.-based energy and chemical conglomerate, both created tangles of interlocking corporations in Luxembourg that may have helped them slash the taxes they pay in the U.S. and Europe, according to the documents obtained by the International Consortium of Investigative Journalists.