CanWest Global Communications and partner Goldman Sachs have agreed on how they will break up Alliance Atlantis Communications as part of their pending $2.3-billion takeover deal.

The companies revealed on Tuesday that the New York investment bank will take possession of AAC’s 50% stake in the CSI franchise, and its 51% stake in Motion Picture Distribution, which will be run by Toronto equity player EdgeStone Capital Partners.

AAC’s 13 specialty channels will go into a joint venture, CW Investments, that will include CanWest’s Global Television network.

CanWest Global will control CW Investments, for now, to avoid running afoul of the CRTC and foreign ownership limits. The Winnipeg-based broadcaster will hold two-thirds of the voting shares and a 36% equity stake in the proposed joint venture. Goldman Sachs will hold the remaining one-third of voting shares and a 64% equity interest.

But the agreement — certain to be scrutinized by the federal regulator — states that CanWest’s equity stake in CWI will climb to 50% if its debt load remains at $778 million, the joint venture’s original debt load, and its EBITIDA is $200 million for the year ending March 31, 2011. The original year-end closing was Dec. 31, 2010.

In other words, how well Global Television does financially in the joint venture, compared to the performance of the AAC channels, will decide how large CanWest Global’s equity stake in CW Investments is at the time Goldman Sachs cashes out.

However, the CRTC could stipulate that CanWest Global must retain control of CW Investments even if its results do not warrant such an outcome.

That could be achieved by Goldman Sachs being forced to off-load some of its equity stake to Canadian pension funds, similar to the Wall Street giant bringing EdgeStone in on the Motion Picture Distribution deal to appease Canadian Heritage.

As part of their agreement, CanWest Global and Goldman Sachs will wind up their broadcasting joint venture by 2013 at the latest. At that point, if CanWest has not bought out Goldman Sachs’ equity interest, ‘then Goldman Sachs will be entitled to sell the CW Investments group, subject to a right of first offer in favor of CanWest, failing which Goldman Sachs will have the right to require CW Investments to effect an initial public offering.’

To finance the AAC takeover, CanWest Global will make a $262-million equity investment — higher than the original $200 million — while Goldman Sachs and a syndicate of banks will contribute the remaining debt and equity.