Dish Network today announced that President CEO Joseph Clayton is retiring on March 31 after nearly four years at the position. Dish Network Chairman Charlie Ergen

Dish Chairman and co-founder Charlie Ergen will succeed him. Ergen previously served as president and CEO of the company.

“Over the last four years, Joe’s leadership has been instrumental to DISH as we have worked to engineer a fundamental transformation of our business,” Ergen said in a statement. “He has set the stage for what will become a new company, and with that he has prepared a new class of management to address the adventures coming our way.”

Serving under Ergen will be EVP/COO Bernie Han, EVP/General Counsel Stanton Dodge, EVP/CHRO Mike McClaskey, EVP/Head of Corporate Development Tom Cullen and Sling TV CEO Roger Lynch.

Ergen founded Dish—formerly EchoStar—more than 30 years ago and has built the company into a satellite-TV provider with nearly 14 million subscribers.

But as Dish’s paid subscriber growth has slowed, the company has become more aggressive in buying spectrum suitable for mobile broadband. Dish says it’s invested $5 billion since 2008 to acquire spectrum assets in secondary market transactions and at auction.

Most recently, Dish, through its bidding partners, bid more than $13 billion in the AWS-3 auction and received more than $3 billion in discounts via the FCC’s Designated Entity (DE) bidding rules for small businesses.

Those airwaves join Dish’s spectrum portfolio that already includes 40 MHz of AWS-4 spectrum, 10 MHz of H Block spectrum and some 700 MHz spectrum.

Dish has yet to indicate what it plans to do with its spectrum but it is nearly deadlines for network coverage build-out requirements on its AWS-4.