(Reuters) – Japans SoftBank Corp is still trying to buy T-Mobile US Inc and merge it with its U.S. wireless carrier Sprint Corp, SoftBank CEO Masayoshi Son said, even though U.S. regulators appear set against a deal. Son told U.S. TV show host Charlie Rose in an interview that if the deal goes through, he would launch a price war to break what he called a duopoly by dominant U.S. carriers ATT Inc and Verizon Communications Inc. We would like to make the deal happen, but there are steps and details that we have to work out, said Son, who had previously declined to comment on whether Softbank was in talks to buy T-Mobile.