By Lilla Zuill

NEW YORK (Reuters) - These are trying times for former AIG Chief Executive Maurice Greenberg.

The one-time Army captain who used to bark orders at underlings at the massive, and now, crippled insurance giant, has been rebuffed of late.

And his personal fortune, once estimated at $1.9 billion (1 billion pound), could be worth considerably less.

Late Tuesday night, the U.S. Federal Reserve Board said the New York Fed will lend up to $85 billion to AIG in a plan aimed at saving the insurer from a "disorderly failure" that could wreak economic havoc.

Since leaving AIG amid an accounting scandal in 2005, the 83-year-old Greenberg's relationship with the insurer he built over a 38-year reign has been largely antagonistic.

However, Greenberg, who controls about 11 percent of AIG's outstanding shares, has gone from launching broadsides against Martin Sullivan, his one-time protege and successor, to offering to help recently installed CEO Robert Willumstad overcome AIG's deepening troubles.

On Tuesday, he sent an urgent letter to Willumstad, appealing for unity for the good of the company. "Whether or not we settle our differences, I remain ready to work with you to do everything possible," he wrote, signing off as Hank, a nickname he took from Hall of Fame baseball player Hank Greenberg.

The offer was snubbed.