Federal Communications Commission Chairman Tom Wheeler expressed his skepticism about a potential merger between Sprint Corp and T-Mobile US Inc in a meeting with Sprint Chairman Masayoshi Son on Monday, according to an FCC official briefed on the matter. Son, chief executive at Tokyo-based SoftBank Corp, which acquired Sprint last year, met with the top U.S. telecommunications regulator alongside Sprint Chief Executive Dan Hesse. Wheeler told Son and Hesse he was highly skeptical of the potential bid by No. 3 wireless provider Sprint to acquire No. 4 rival T-Mobile, according to the FCC official, who was not present at the meeting. Wheeler said he would keep an open mind about the potential transaction, according to the official, and generally echoed comments made last week by antitrust chief William Baer, who gave long odds to a regulatory approval of mergers between any two of the top four wireless phone companies.