This is a big deal. Chang has been at the center of DirecTV’s negotiations with broadcast and pay TV channels since 2006 — including the recent dust-up with Tribune — and is highly regarded throughout the industry. Before joining the No. 1 satellite company he was interim CFO at Charter Communications, a member of the original management team at the New York Yankees’ YES Network, and an exec at AT&T Broadband. CEO Michael White says that Chang wants to “take his career in a different direction.” Here’s the release:

EL SEGUNDO, Calif., May 29, 2012 – DIRECTV announced today that after more than six years of successfully leading its programming acquisition, original content, regional sports networks and ad sales groups, Derek Chang will leave his position as executive vice president of Content Strategy and Development at the end of the year. Succeeding him will be Dan York, former president of Content and Advertising Sales for AT&T, who will join DIRECTV in early July as executive vice president of Programming, and Chief Content Officer.

York, who will report to Mike White, chairman, president and CEO of DIRECTV, will initially lead DIRECTV’s efforts in programming and content rights, and then oversee the content and ROOT Sports teams as Chang transitions out of his role at year-end.

“I want to thank Derek for his tremendous leadership over the years in establishing DIRECTV as the very best in content highlighted by DIRECTV’s preeminent position in HD and its continued superiority in sports programming,” said White. “We understand Derek’s desire to take his career in a different direction but I personally appreciate his advice and guidance during my own entry into the industry and his willingness to work with me on a thoughtful transition over the course of this year.”

“I am extremely proud to have been part of such a tremendous team and such great successes at DIRECTV,” said Chang. “Under Mike’s leadership I am confident that the company will continue to perform at the highest levels in this industry.”

White added, “While we’re sorry to see Derek leave, I’m delighted that after an extensive search both inside and outside the company, we have selected someone of Dan York’s talent and ability to replace Derek. Dan brings an extraordinary breadth of experience to DIRECTV, from helping to build the AT&T U-verse video platform from the ground up to successfully managing all aspects of the content business including distribution, marketing and acquisition of linear, VOD, PPV and sports programming. I know Dan will ably continue Derek’s legacy of strong, imaginative content leadership.”

“I’m looking forward to working with Derek and his programming group, who I have long admired for their tenacity and creative thinking,” said York. “This is an exciting opportunity to not only be a part of Mike’s talented executive team, but to have the advantage of DIRECTV’s unequaled reach and scale to continue building an affordable, engaging content offering that will take DIRECTV customers’ viewing experience to a new level, both inside and outside the home.”

As president of Content and Advertising Sales for AT&T, York developed the content strategy and offering for AT&T U-verse and oversaw AT&T’s content activities across all of its platforms, including TV, online and mobile, which serves more than 100 million customers. In six years, he helped build U-verse from zero to more than $9 billion in annualized revenue while managing billions of dollars in content expense.

York was previously head of Programming and Development for In Demand Networks, the leading VOD, PPV, and sports provider. Before that he worked for 12 years at HBO, most recently managing the distribution, marketing, sponsorship, and select content acquisitions and programming operations for HBO’s Sports PPV business.

York holds master’s and bachelor’s degrees from Michigan State University.