The hearing was over Gillette's lawsuit that claims Schick's Quattro, a four-bladed razor, uses the same technique to stack the blades in the cartridge as Gillette's Mach3 three-bladed razor and otherwise violates Gillette patents. Gillette is seeking a preliminary injunction to stop Schick from selling Quattro, which went on the market in September.

During the first of a scheduled two-day evidentiary hearing, Gillette presented witnesses who tried to show the affect Quattro has had on its business and to also defend the patent.

One Schick lawyer suggested during cross-examination that Gillette's three-bladed technology was merely a natural progression from two-bladed technology introduced in the 1970s.

John Terry, retired head of research and development for Gillette, rejected that suggestion.

"Having struggled with the problem for over 20 years, I don't think it was obvious and if it was so obvious, Schick-Wilkinson would have done it," he said.

"There's nothing anywhere that says four blades," Richard Rochford, an attorney for Schick, said of Gillette's patent that covers its top-selling Mach3. In fact, Rochford said the technical measurements in Gillette's patent do not leave room for a fourth blade.

But John Nathan, an attorney for Gillette, said that any razor head that includes any group of three blades would be covered by Gillette's patent. He likened the Quattro to adding a fifth leg to a four-legged table.

Lawyers for software company SCO Group could wind up with 20 percent of the proceeds if the company were to be sold or reach a legal settlement, according to a recent document filed with regulators.