Liddy took the helm of AIG, once the world's largest insurer, two weeks ago, after the government agreed to lend AIG $85 billion dollars in exchange for a 79.9 percent stake in the company to stave off potential bankruptcy protection.
AIG has been preparing to sell off assets to begin paying off that loan as a group of shareholders seeks to keep control of the company. Among the assets AIG is considering selling is its aircraft leasing unit, reinsurer Transatlantic Holdings, and London City Airport, according to reports.
Greenberg made the request in a letter dated Sept 29, and said the process of the selling of assets has been taking place "without transparency and without providing the opportunity for the participation of alternative purchasers" that would help AIG get the best price for shareholders.
The authenticity of the letter, first reported by the Wall Street Journal's Website on Tuesday, was verified by Greenberg's spokesman Glen Rochkind.
In the letter, Greenberg told Liddy he has a fiduciary duty to obtain the best possible price and "you cannot do so by ignoring offers from qualified potential purchasers."
"AIG welcomes any reasonable expressions of interest in the businesses we plan to sell," said AIG spokesman Joe Norton, who confirmed Liddy's receipt of Greenberg's letter. Norton declined to comment further.
Greenberg left AIG in 2005 following an accounting scandal under the threat of prosecution from then New York State Attorney General Eliot Spitzer. He has denied any wrongdoing.