With investors in the world’s largest insurer AIG seeing billions slip through their fingers almost any week of late, they’re agitating for change – even wanting to bring back its legendary but ousted chief Hank Greenberg.

AIG’s getting hammered not only by Wall Street traders who pushed shares to their lowest price in a year, but also in a criminal trial over a widespread profits-rigging scandal. The scandal cost Greenberg his job but he was never charged with any wrongdoing.

Deeper bruising is coming from the surprise admission in regulatory filings last week that AIG has inflated its books by more than $4.9 billion due to sloppy accounting on junk mortgage paper and other risky bets.

The snafu added more pressure on the low-key caretaker chief of AIG – Martin Sullivan, 53 – who was supposed to get AIG’s house in order after Greenberg stepped down in 2005 amid a state probe of questionable practices inside AIG that led to the federal case.

Analysts fear that the separate accounting debacle last week – essentially using outmoded accounting models to paint a rosy picture of its junk paper – could be concealing other skeletons in the closet. Its shares have lost $71 billion in market value in a year.

In other image-bashing late last week, A.M. Best, the gold-standard for rating insurers, began its painful process of downgrading AIG over “uncertainties” in its assets. Moody’s slashed AIG’s stable credit rating to “negative.”

One AIG insider said the accounting debacle “casts doubt on Martin Sullivan.”

“It raises questions whether AIG has changed as much as claimed in the past three years under Sullivan,” said Ron Shelp, a former AIG executive who worked directly for Greenberg and authored “Fallen Giant, the Amazing Story of Hank Greenberg and the History of AIG.”

He says many investors would like to see the 82-year-old Greenberg back at the helm, de spite his backing down a month ago from a proxy fight to win more control at AIG.

“In retrospect, one might say it’s unfortunate that Greenberg had to withdraw his proxy battle to regain control of AIG,” said Shelp. “He’s not charged with any crimes, and now would be a perfect time for him to win that battle.”

Greenberg’s spokesman didn’t return calls.

Greenberg, who controls 13.6 percent of AIG, has complained AIG is now run by “lawyers who don’t know anything about business.”