Alaska Air Group (NYSE: ALK) appointed Mike Sievert, former CEO of T-Mobile, to its board of directors. Sievert currently serves as vice chairman of T-Mobile's board.

During Sievert's tenure as T-Mobile CEO, the company's market value increased from approximately $60 billion to about $260 billion. He joined T-Mobile in 2012 as chief marketing officer when the company's market value was less than $10 billion.

"Mike is a proven leader who understands how to grow a business, strengthen customer relationships and execute at a global scale," said Board Chair Patty Bedient. "His experience leading a highly competitive, customer-focused company, combined with his strong connection to Seattle, will make him a valuable addition to our board."

Sievert has lived in the Seattle region since 2002 and serves on the Starbucks board of directors. He is also a licensed pilot. Before joining T-Mobile, he held leadership positions at Microsoft, AT&T, E*TRADE, IBM and Procter & Gamble. He earned a bachelor's degree in economics from the Wharton School of the University of Pennsylvania.

"I've long admired Alaska's focus on operational performance and doing the right thing for their guests," Sievert said. "I'm looking forward to contributing to the airline's continued growth and helping strengthen its position as a global airline."

With Sievert's appointment, the board has 10 independent director seats. CEO Ben Minicucci serves as a non-independent director. Sievert will serve on the Innovation and Safety committees. Alaska Air Group directors serve one-year terms upon election at the company's annual meeting of stockholders.