A new life insurance-policy rider has the potential to raise more than $260 billion for charities in North America by the year 2000, Prudential Insurance Co. of America said.

A "Charity Plus" rider could raise up to $164.4 billion in the United States by 1995 and $240.6 billion by 2000, according to the company's projections.In Canada, the rider could raise up to $15.4 billion in five years and $22.5 billion in 10 years.

The rider, now available to Prudential policyholders in Canada, will be tested in the United States in a pilot project early next year.

Ron Barbaro, who took over as worldwide president of Prudential a week ago, acknowledged in a telephone interview from his New Jersey office that the rider's financial potential windfall for charities was "astronomical."

Barbaro said the figures were estimated on the basis that all insurance companies sold "Charity Plus"-type riders worth 10 percent of the face value of policies over $25,000 to all their clients.

"I realize the figure is optimistic, but I wanted to illustrate how this new way of giving could have a tremendous impact," Barbaro added.

Policyholders can purchase a charity rider for either 5 percent or 10 percent of the face value of a life insurance policy to a maximum of $10,000. The rider is available for all new Prudential life insurance policies with face amounts of at least $25,000.

The money is later paid as a death benefit to any registered charity selected by the client.

For example, Barbaro said, a holder could opt for a $50,000 policy with a 5 percent charity rider. The policyholder's estate would receive $50,000 and the charity would receive $2,500 after the holder died.

Barbaro said Prudential is making available to other insurance companies details of the "Charity Plus" rider because it will work only if all companies are offering similar riders.