An Illinois Supreme Court ruling allowing criminal prosecution of business executives for employees' workplace injuries could produce an unpredictable patchwork of local safety standards, the head of a state business group says.

The ruling could affect the case of Utah businessman Michael T. MacKay.The state's highest court said Thursday that five officials of Chicago Magnet Wire Co. could be prosecuted on charges including aggravated battery and reckless conduct in connection with injuries to 42 employees that allegedly resulted from unsafe working conditions.

Overturning lower court decisions, justices ruled without written dissent that the federal Occupational Safety and Health Act, which governs workplace safety, does not bar criminal prosecution for unsafe working conditions.

Cook County State's Attorney Richard M. Daley, whose office is prosecuting the case, said the decision has "national importance" and will safeguard workers from "a very few unscrupulous employers who put profits above the safety of their workers."

But Arthur Gottschalk, president of the Illinois Manufacturers Association, warned that local prosecutors might apply varying safety standards and back up their judgments with criminal sanctions.

Harvey Silets, a attorney for one of the defendants, has predicted that the case ultimately will go to the U.S. Supreme Court.

"It is of such significant national importance that it will more than likely be taken up on appeal," Silets said after arguing the case last year.

Thursday's ruling also set a possible precedent for another Illinois case in which three executives of Film Recovery Systems Inc., a suburban Chicago company, were convicted of murder and sentenced to prison in the death of a factory worker who was exposed to cyanide on the job.

That case, currently on appeal, was the first in U.S. history in which corporate executives were convicted of murder in a safety-related workplace death.

MacKay, a former company director, was one of those charged, but Gov. Norm Bangerter and former Gov. Scott M. Matheson thrice rejected prosecutors' attempts to extradite him to Illinois.

MacKay, who has said his interest in the company was purely financial, declined comment on the ruling late Thursday.

"We're disappointed," said MacKay's attorney, Richard B. Farrari. "We just don't know what action the state's attorney will take, whether he will seek extradition now or wait until the matter is ultimately disposed of by the Illinois Supreme Court."