Mr. Skilling, the former Enron chief executive, was testifying for a third day at his federal fraud and conspiracy trial, which is in its 11th week.
Such discounts are permissible under federal fraud and abuse laws, the government said, in a clarification requested by the hospital industry.
Sholom Rubashkin as the highest ranking day-to-day corporate officer was charged with federal financial fraud and sentenced to 27 years in prison in June 2010.
Whether the lawyer, Michael W. Ramsey, 66, will be able to return to Mr. Lay's federal fraud and conspiracy trial before it concludes is unclear.
The Bush administration told drug companies today that many of the techniques they use to sell their drugs run a high risk of violating federal fraud and abuse laws.
The government informed the industry that many practices commonly used in the marketing and sale of prescription drugs could run afoul of federal fraud and abuse laws.
A court statement said the maximum sentence for federal fraud was 10 years in prison, a fine of $5 million, or both.
Both men were convicted on federal fraud and embezzlement charges after the thefts were disclosed by The Washington Post in 1992.
Those four have already pleaded guilty to federal fraud and conspiracy charges and are cooperating in the Justice Department's investigation.
The retrial of former Mayor Kenneth A. Gibson on federal fraud and bribery charges was abruptly adjourned yesterday for two weeks.