Maurice Greenberg, the former chairman of American International Group Inc., today said the Federal Reserve System should provide a bridge loan for AIG if the private markets will not.

The cash would help AIG, New York, solve “a liquidity problem, not a solvency problem,” Greenberg said.

Greenberg spoke this morning on CNBC as bankers, state regulators and federal officials met at the New York Fed offices in an effort to come up with a $75 billion financing package for AIG.

It is in the “national interest that AIG survive,” Greenberg said.

If the rating agencies held downgrades in abeyance for 90 days, that could give AIG the time to conduct a rights offering and arrange to sell assets, Greenberg said.

AIG “is a national treasure,” Greenberg said. “Letting AIG go down would be a tragic mistake.”

If AIG filed for bankruptcy court protection, resolving the company’s trades with counterparties “would take years,” Greenberg said. “You are creating a systemic problem” by forcing AIG into bankruptcy.

“There is no business like AIG,” Greenberg said. “It affects everything we can do in the world. It would be a loss to America.”