Madison Square Garden didn’t have to look far to find a new CEO for its regional sports networks, which will become a distinct corporate entity at the end of this month when the company spins off the sports and entertainment assets.

Andrea Greenberg, who’s EVP of MSG Media, will become chief executive reporting to Executive Chairman James Dolan, the company says today. The CFO will be Bret Richter, who’ll move to MSG from Dolan’s Cablevision, where he’s now EVP of Corporate Finance and Development.

The announcement comes as the MSG board set September 30 as the date for the spinoff. It will create a new entity with venues including Madison Square Garden, Radio City Music Hall, The Beacon Theater, and The Forum as well as sports teams including the New York Knicks, the New York Rangers, and the Hartford Wolf Pack. That entity will be called Madison Square Garden Co, and will be run by MSG’s new CEO, David “Doc” O’Connor.

The existing company, which Greenberg will run, will change its name to MSG Networks. It will include sports channels MSG Network and MSG+.

“We are confident that this transaction will further enhance the long-term value potential of both companies as each continues to build on its considerable record of achievement,” O’Connor says.

Greenberg joined MSG in 2010 when Cablevision spun it off. Prior to that she spent 25 years at Cablevision’s networks operation, Rainbow Media. The channels what weren’t part of MSG were spun off in 2011 as AMC Networks.

MSG has been swirling with changes since late last year when it announced the plan to divide itself. In February Cablevision Vice Chairman Gregg Siebert, a former head of Merrill Lynch’s global media practice, became Vice Chairman — leading to wide speculation that the Dolans may sell at least one of the companies. In. March, MSG CEO Tad Smith left to run Sotheby’s auction house.