After all of the talk of splitting itself into two pieces, a "bad" part and a "good" part, Ambac (NYSE: ABK) will probably operate as only one company. The theory had been that the healthy muni-bond insurance operation should be separated from the business that insured more risky derivative instruments.

Breaking the company in half always had a number of complications, the worst of which is what would happen to common shareholders? Would they get shares in the "good" part of the business? Perhaps, but outside firms putting in money might want to keep that for themselves. Shares in the "bad" part of the business would probably be worthless.

Another issue is the legal troubles a split might cause. According to the FT, this raised the "possibility of lawsuits by banks and other groups that bought insurance on CDOs and other structured products."

Ambak is almost certainly going to have to live with its two businesses under that same roof. If the structured finance business continues to fall apart, the real question is how much more money will the insurance company have to raise.

Douglas A. McIntyre is an editor at 27wallst.com.