* Sprint, T-Mobile shares have fallen since deal announcement
* Scepticism over chances of deal getting approved in U.S.
* SoftBank's Son "not involved at all" in getting deal approved
* Son previously praised by Trump after pledging to invest in U.S. (Recasts, adds details of Claure's new role)
By Sam Nussey
TOKYO, May 3 (Reuters) - SoftBank Group Corp's Chief Executive Masayoshi Son is not involved in trying to get the proposed merger of U.S. wireless carriers Sprint Corp and T-Mobile US Inc approved, Sprint's outgoing chief executive said on Thursday.
Marcelo Claure's comments dampen speculation Son may use his ties to U.S. President Donald Trump to ease passage of the merger of the third- and fourth-largest U.S. wireless carriers, which faces intense scrutiny from U.S. authorities.
Son, founder of Sprint's controlling shareholder SoftBank, is "not involved at all" in efforts to complete the $26 billion all-stock deal, Claure told Reuters in a phone interview.
Sprint and T-Mobile announced on Sunday they had agreed to a merger in which Sprint would acquire T-Mobile. The deal allows the combined entity to bulk up in order to better invest in next-generation 5G wireless technology.
But the deal faces regulatory hurdles starting with scrutiny from the Department of Justice and the Federal Communications Commission.
Other steps include a national security review by the Committee on Foreign Investment in the United States, the U.S. federal states, and Trump's White House.
In late 2016 Son met Trump and pledged to invest $50 billion and create 50,000 new jobs in the United States, winning praise from the then president-elect.
"It's always good to have a good relation, to be well perceived by the head of state but ... these are non-political processes," Claure said.
Hit by doubts over the deal's prospects, Sprint's shares have fallen 20 percent since Sunday's announcement. T-Mobile's shares are down almost 12 percent.
"There is a scepticism with our ability to be able to get this merger approved," Claure said adding it would be a top priority in his new role.
Claure is stepping down from the top job at Sprint to become the chief operating officer at SoftBank Group and chief executive officer of SoftBank Group International, the technology and telecoms company's sprawling international investments arm.
The latter role has been vacant since the departure of Nikesh Arora, the former Google executive who was once set to become Son's successor.
Son has pledged to create a group of global companies employing technology such as connected devices and artificial intelligence.
But investor confusion over how mutually supportive such investments are has helped contribute to the "conglomerate discount" that has weighed on SoftBank's share price.
"There are so many synergies within the group that we need to organise," Claure said, citing the example of closer cooperation over chip designs between SoftBank subsidiary ARM Holdings and other portfolio companies.
Michel Combes, Sprint's chief financial officer, will take over as Sprint CEO by May 31. Claure will become executive chairman. (Reporting by Sam Nussey in Tokyo; Editing by Muralikumar Anantharaman and Stephen Coates)