Legere, who is positioning his company as the "un- carrier" upending the mobile-phone industry, showed up at the AT&T-sponsored event in Las Vegas on Monday night for attendees of the International Consumer Electronics Show. Shortly after appearing in a Twitter photo posted by CNET reporter Roger Cheng, Legere was shown the door.
"Some security guards escorted him out. It was crazy," Cheng wrote in a Twitter message. Legere later told technology news site Re/code he had gone to the party to see rapper Macklemore perform.
Since taking over as CEO in 2012, Legere has been undercutting larger competitors with cheaper plans, quicker upgrade privileges and free international roaming. Along the way, he has needled AT&T, the second-largest mobile phone company, and its CEO Randall Stephenson, calling his network "crap" at last year's CES.
T-Mobile Chief Financial Officer Braxton Carter joined Legere at the AT&T event, Cheng reported. Legere missed his chance to see Macklemore, who performed after the CEO was booted, Cheng said.
Mark Siegel, an AT&T spokesman, and Janice Kapner, a T- Mobile spokeswoman, didn't respond to messages seeking comment on the incident.
The competition has intensified between T-Mobile and AT&T in part because they use a similar network technology that makes it easier for customers to keep their phones when they change providers. AT&T announced last week it would give T-Mobile customers as much as $450 in credits to switch over.
"Memory problems, eh Randall?" Legere said this week on Twitter. "Remember in September you said T-Mobile hadn't impacted your business. Yeah, that's why you're bribing customers!"
The growing acrimony between Legere and AT&T reveals a sharp contrast to an earlier, friendlier history when the two companies planned to unite in a $39 billion takeover of T- Mobile. Facing opposition from regulators, AT&T killed the deal in December 2011.
The collapse of the transaction required AT&T to pay a breakup fee valued at about $7 billion. The penalty package included cash, airwaves and network-sharing agreements, which have helped boost T-Mobile's competitive stature.
T-Mobile has used that cash and spectrum to upgrade its network. Yesterday, the company agreed to a deal with Verizon Wireless valued at $3.3 billion to acquire a big swath of low- band frequencies - a type of spectrum that Chief Operating Officer Jim Alling has said are the missing piece of its network coverage.
In the last few weeks, T-Mobile, the fourth-biggest mobile- phone company in the U.S., has been linked in merger speculation with Sprint Corp., the third-largest. Masayoshi Son, CEO of Sprint majority owner SoftBank Corp., has talked to banks about financing a bid for control of T-Mobile, people familiar with the matter said in December.
T-Mobile has been able to back up its upstart corporate persona by posting consecutive quarters of gains in monthly subscribers. T-Mobile, based in Bellevue, Washington, led all carriers by adding 1.47 million of those lucrative customers in the second and third quarters of 2013.
AT&T and Verizon Wireless, the nation's largest wireless carrier, have mimicked some of T-Mobile's service plans. And Dallas-based AT&T has started a marketing push touting the supremacy and speed of its network.
Unlike his fellow U.S. mobile-phone CEOs, who don't actively maintain Twitter profiles, Legere has been prolific on the social-media site. His posts have established him as a confrontational executive, earning him more than 50,000 followers -- 10 times as many as AOL Inc. CEO Tim Armstrong, though only a 10th as many as News Corp. Chairman Rupert Murdoch.
On Twitter, Leger makes references to Batman and TV shows, taunting rival carriers and republishing his followers' messages, even those that tend toward the risque.
"You can't ignore me," he wrote on the site last month, "and neither can our competitors!"