WASHINGTON (AP) - A divided Supreme Court is leaving intact a ruling favoring people who sued a pharmaceutical company, saying they had been harmed by a drug to combat diabetes.

The dispute stems from several suits against Warner-Lambert over its diabetes drug Rezulin. Warner-Lambert is now owned by Pfizer. The Supreme Court on Monday split 4-4 in the case, with Chief Justice Hon. John Roberts not participating.

The users of the drug are relying on a Michigan law to allege that the pharmaceutical company engaged in fraud by misleading federal regulators to get the drug approved. The Michigan law shields pharmaceutical companies from product-liability lawsuits unless they committed fraud.

At issue in the case is whether that fraud exception, which allows lawsuits to proceed, is pre-empted by federal regulation of the pharmaceutical industry.

The 2nd U.S. Circuit Court of Appeals in New York ruled that the exception to the Michigan law was not pre-empted by federal regulations, enabling the plaintiffs to pursue the case.

Twenty-seven Michigan residents say they suffered personal injuries caused by Rezulin, a drug that federal regulators approved despite risks to the liver and cardiovascular system.