Comcast-owned thePlatform announced this morning that co-founder Ian Blaine was leaving his CEO post effective June 20 to move into a strategic advisor role with the white-label video publishing company.

The Seattle-based company is replacing Blaine internally with co-CEOs Marty Roberts, its current head of sales and marketing, and COO and CFO Jamie Miller.

“Marty and Jamie are exceptional leaders, with the proven background, vision and passion to guide thePlatform into the future,” said Sam Schwartz, chief business development officer of Comcast Cable. “Over the years, thePlatform has played an important role in the growth of multi-screen video for both Comcast and the broader industry, and I am confident that will continue under the leadership of Marty and Jamie.

“I’d like to thank Ian Blaine for his leadership and wisdom during the last decade of thePlatform’s growth. We look forward to continuing to work with him as a strategic advisor.”

Roberts and Miller will jointly manage overall corporate strategy and execution, but will divide up specific areas and responsibilities. Roberts will add to his current responsibilities by directing the company’s engineering and technology activities.

Alan Ramaley, CTO, and Mike Horwitz, senior vice president, engineering will both report to Roberts. Prior to joining thePlatform in 2006, Roberts served in leadership positions at and RealNetworks.

Miller currently oversees the company’s administrative organizations, as well as ownership of the company’s consulting services business. As co-CEO, he will add to those responsibilities the oversight of expansion in Europe and the Middle East. Simon McGrath, general manager, Europe will report to Miller.

Before joining thePlatform in 2010, Miller was the president of the desktop division of Blinx, served as the CFO and COO of Microsoft’s largest US business applications consultancy.

Comcast, which bought thePlatform in 2006, recently bought online ad insertion vendor FreeWheel.

In addition to Comcast, customers for thePlatform include: A+E Networks, BT, Cablevision, CBC, Cox Communications, E!, the Golf Channel, HIT Entertainment, Liberty Global, NBC Local Media, NBC Sports Regional Networks, Outdoor Channel, Oxygen, Rogers, Shaw Media, Style, Syfy, Time Warner Cable, Travel Channel Media, truTV, and USA Network.

“I’ve spent a third of my life focused on thePlatform, and I’m making this transition now because I can do so on a high note, and with the confidence that the company will continue its success under the leadership of Marty and Jamie,” said Blaine. “Marty and Jamie have proven that they can grow the business, maintain our culture and chart new territory, which were essential prerequisites for succession planning. Together with the rest of our remarkably talented team, I know they will continue to serve our customers and partners with utmost devotion.”