Lawyers for Star Scientific Inc. (STSI) and R.J. Reynolds Tobacco Co. made their final bid Monday to sway jurors in a high-stakes case involving Star's patent claim to a new tobacco-curing method that substantially reduces the formation of certain cancer-causing toxins.

Star, which is seeking several hundred million dollars from RJR for patent infringement, said its patented method for reducing certain toxins in cured tobacco, known as tobacco specific nitrosamines, was a revolution in the tobacco industry.

"Nobody could believe it," Star lawyer Richard McMillan said in his closing argument to jurors. "It was completely surprising to the industry."

McMillan said RJR, a unit of Reynolds American Inc. (RAI), "got wind" of the small company's patent and encouraged its farmers to practice Star's invention without permission.

McMillan told the jury that Star was a different kind of tobacco company, one dedicated to making products that are less harmful to tobacco users. "We need to have our patent rights respected if we're going to have an impact in the future," he said. "That's just a fact."

RJR lawyer Richard Kaplan said his company had invented its own tobacco-curing method that reduced the toxins and didn't need to copy Star's.

"Star is taking credit for the hard work and diligent efforts of other people," he said.

Kaplan said RJR had been looking at the toxin problem for years and invested substantial time and money coming up with a solution.

He called Star's tobacco-curing method unconventional and prohibitively expensive.

Kaplan also argued that Star's patent was not valid, saying it wasn't specific or tangible enough for anyone to understand the invention or how to practice it.

Monday's closing arguments, which took place in a small federal courtroom packed with spectators, concluded four weeks of trial proceedings. The case was submitted to the jury late in the afternoon.

The outcome could go a long way to determining Star's fortunes. If it prevails, it hopes to reach lucrative licensing agreements with other tobacco companies. If the jury decides that RJR infringed Star's patents, the case will proceed to a second trial phase to determine how much RJR owes in damages.

U.S. District Court Judge Marvin Garbis, who has presided over the trial, said Monday that Star and RJR haven't found a single point of agreement throughout the whole trial. Garbis said the sides were still arguing Sunday night and into the wee hours of Monday morning on the proper jury instructions to guide the deliberations.

"It has been a struggle of Titanic proportions," Garbis said.

-By Brent Kendall, Dow Jones Newswires; 202-862-9222; brent.kendall@dowjones.com