The investors, which include the China Aviation Industrial Fund and P3 Investments, have an option to buy another 9.9 percent stake in International Lease Finance Corp., but AIG said it would keep 10 percent.
The deal puts the total value of ILFC at $5.28 billion.
The Los Angeles Times reported Monday the firm has more than 1,000 planes it rents to many of the world's major airlines.
The deal is a further paring down of the insurance giant that needed cash to pay down its massive government bailout it took after the 2008 financial crisis.
Treasury Department said Monday it had made plans to sell the remainder of its AIG assets it acquired with the $182 billion in emergency aid granted to the company through the Troubled Asset Relief Program, known as TARP.
The federal government still owns 234,169,156 shares of AIG, The Hill newspaper reported.
The Treasury Department would not be free and clear of AIG after the sale, as it will still hold warrants to purchase company stock that were part of the bailout deal.