CHICAGO — The government crackdown on corporate crime is coming under pressure to back off amid intense business lobbying and adverse court rulings.

Since the convictions in May of Enron Corp. honchos Jeffrey Skilling and Kenneth Lay, federal authorities have voluntarily stepped away from certain hardball tactics aimed at forcing companies to turn against accused executives.

An even greater retreat could be in the offing as the U.S. Chamber of Commerce and other business advocates extend their campaign to rein in what they consider excessive enforcement efforts. On top of that, a string of reversals on appeal has raised fresh doubts about recent government victories targeting criminal fraud among the business elite.

Some close observers sense a tide turning. "Every month that goes by, the pushback gathers more steam," says Douglas Berman, a law professor at Ohio State University. "It's a realization the tough-on-crime campaign against white-collar offenders was at risk of being too tough."

On Jan. 5, appellate judges tossed out most of the charges against top executives at Westar Energy, who were accused of looting the Topeka-based public utility in a case dubbed the "Kansas Enron."

Though the Justice Department touted those 2005 convictions as proof that "no boardroom is above the law," Denver's 10th Circuit Court of Appeals found that prosecutors based their sweeping indictment on a "thin legal thread."

As standards shift, even the judge who presided over the Enron trial has conceded that Skilling has a good chance of seeing one count of conspiracy conviction overturned.

While U.S. District Judge Sim Lake ruled that Skilling's 18 other convictions were likely to stand on appeal, some legal experts believe Enron's "smartest guy in the room" may yet win on wider issues. That could lead to a reduction in the 24-year sentence he began serving last month at a low-security Minnesota prison.

Skilling's attorney, Dan Petrocelli, says softer attitudes toward white-collar crime can only help as he presses for release of his client.

"He's very optimistic, as we are, that he won't be there very long," Petrocelli says.

NEW SKEPTICISM

At Wayne State University law school, white-collar-fraud specialist Peter Henning agrees that Skilling could benefit from new skepticism about "the aggressive use of criminal laws against corporate executives. In these very high-profile cases, there are more reversals. If I were Jeff Skilling, I'd have more hope."

Justice Department spokesman Brian Roehrkasse says no one at his agency is retreating from aggressive prosecution of corporate fraud. "The numbers certainly don't bear that out," he says.

"We remain extremely committed to the prosecution of those in the corporate community who would violate the trust of their employees, of the investing public, or both."

Federal prosecutors have tallied more than 1,000 corporate fraud convictions since Enron's 2001 collapse, and the ongoing investigation into options backdating by pay-hungry executives stands to yield more. But the task has been challenging.

The conviction of Lay, who died July 5, and Skilling came amid defeats in other Enron-related matters, most notably the overturned conviction of Chicago's Andersen accounting firm and the withdrawal of a guilty plea from lead auditor David Duncan.

In a related case involving Enron-owned power plants in Nigeria, a group of Merrill Lynch executives saw their convictions reversed in a decision that weakened an element of the fraud statute.

'MIXED RESULTS'

For every duly convicted Bernard Ebbers and Martha Stewart, it seems, a KPMG accountant or Frank Quattrone scores one for the defense.

In a 2006 study tracking some of the most prominent corporate trials, Washington University researcher Kathleen Brickey found "surprisingly mixed results," with juries convicting 18 defendants, acquitting 11 and deadlocking on 15 others. That trial record, which lags well behind the government's success rate in criminal litigation overall, supports the business-lobby criticism that prosecutors were "trying to find crimes where none really exists," the Brickey study noted.

Yet after factoring in guilty pleas, cooperation agreements and retrials, the prosecutors' track record in complex corporate cases improves to "a respectable, if not spectacular conviction rate," Brickey concluded. Even so, the jury is still out on the wisdom of using "individual criminal prosecutions to address systemic corporate fraud," she found.

Meanwhile, business advocates have targeted enforcement aimed at corporations rather than individuals. They tallied a victory in December when the Justice Department put new restraints on prosecutors who were demanding the legal communications of companies under threat of indictment.

The routine practice of forcing those businesses to waive attorney-client privilege as a condition of settlement violates the rights of defendants, critics say. And even the new restraints fail to go far enough in protecting companies from being indicted, they assert.

"We've learned something from Andersen, where thousands of innocent people were ruined," says Hal Scott, a Harvard University law professor who heads a pro-business lobbying group. "You should only prosecute when the whole company is criminal from bottom to top."

Skilling took heart from a Dec. 12 decision of the 5th Circuit Court of Appeals that identified "serious frailties" in many of his convictions because of the reversal in the Enron-Nigeria case.

But that same appellate decision raised no specific doubts about five convictions for lying to auditors, and it concluded that Skilling should remain in prison because he is unlikely to win a reversal on all his crimes.