BIRMINGHAM, Ala(Reuters) - A jury in Alabama ruled on Tuesday in favor of the old Monsanto company, now Pharmacia, in a case in which it was accused of manufacturing PCBs that caused arthritis and diabetes.

Five plaintiffs who lived in Anniston, Alabama, where the company made polychlorinated biphenyls until the 1970s and had been dumping chemicals into local creeks, brought individual lawsuits against Monsanto at a state court.

The five are all senior citizens who suffer from arthritis or diabetes. They are the first of around 3,000 individuals filing lawsuits, according to plaintiff attorney Frank Davis of Davis, Norris, LLC.

"This jury... ruled that the five plaintiffs in this case failed to prove their allegations that their common illnesses were caused by exposure to PCBs many years ago from an Anniston, Alabama, plant," defense attorney Augusta Dowd said in a statement.

"The five plaintiffs are 67 to 89 years old and they have a number of well-established health factors that could explain their health condition, including obesity, diet, tobacco smoking, family history and others," Dowd said.

"There is no credible evidence that their illnesses are linked to PCB exposure from the plant in Anniston, where PCBs have not been manufactured for more than 30 years," the statement said.

Pharmacia, a unit of Pfizer Inc, is the named defendant in the case, but Monsanto has an obligation to defend the case, Dowd said.

It was not possible to obtain immediate comment from the plaintiffs.

Much of the 2-week case revolved around whether or not the PCBs actually caused diabetes and arthritis or whether they were merely associated with it.

Monsanto manufactured PCBs, classified as probable human carcinogens by the U.S. Environmental Protection Agency, at the plant for about 40 years. They were commonly used as lubricants and coolants for electrical equipment.

The U.S. government banned most uses for PCBs in 1979.