BANGOR – The maker of Gifford’s Ice Cream is going on the offensive to protect one of its best-loved flavors – Maine Black Bear.

The Skowhegan-based Gifford’s Dairy Inc. filed a lawsuit last week in U.S. District Court in Bangor charging that a Massachusetts firm not only is infringing on its trademarked ice cream but also is trying to compete unfairly with Gifford’s by attempting to associate itself with the state of Maine.

Richardson’s Farms Inc. of Middleton, Mass., also makes an ice cream called Maine Black Bear, which is not trademarked, according to Gifford’s attorney, Peter Black of Portland. He said Monday that in response to a letter last May asking Richardson’s to stop using the name Maine Black Bear, the Massachusetts firm filed a petition seeking to cancel Gifford’s trademark registration.

“We feel strongly that a Massachusetts company shouldn’t poach our Maine Black Bear,” said Black. “We’re prepared to see this through” to a jury trial.

The ice creams are similar, according to descriptions on the companies’ Web sites. Gifford’s Maine Black Bear is composed of a vanilla ice cream base with swirls of black raspberry syrup and chocolate candies filled with liquid black raspberry. Richardson’s Maine Black Bear is described as a red raspberry ice cream with chocolate chips and chocolate-covered raspberry truffles.

The outcome of the matter could depend on which company can prove it made its Maine Black Bear flavor first.

Gifford’s claims it created the flavor in 1992, began selling it the next year and applied for its trademark in June 2000. On Jan. 29, 2002, Gifford’s was granted its trademark by the United States Patent and Trademark Office without opposition from Richardson’s or any other firm.

Richardson’s claims, according to the lawsuit, that it began selling its Maine Black Bear in 1994 in Maine, New Hampshire and Vermont. Richardson’s is available seasonally at some dairy bars in York County, said Black. Gifford’s is sold in Maine, New Hampshire, Vermont and Massachusetts at Shop ‘n Save grocery stores, according to information on its Web site.

Both firms share a similar history. Richardson’s is a family-owned business that, like Gifford’s, grew out of a dairy farm operation. The Richardson family, which has farmed the same land in Middleton for more than 300 years, began making and selling ice cream at a seasonal dairy bar in 1952.

Gifford’s has been operating in Maine for more than 40 years. The company began making ice cream in 1980 and three years later sold its milk-processing division to concentrate on ice cream.

The lawsuit attributes some of Gifford’s success to its emphasis on using Maine-made products and its collection of “unique and creative flavors with fanciful names that highlight the company’s connection to Maine.” Other flavors include Maine Black Fly, Maine Deer Sign, Maine Blueberry, Maine Mint Avalanche and Maine Maple Sundae. Gifford’s is alleging trademark infringement only for its Maine Black Bear flavor.

The lawsuit asks the court to:

. Order Richardson’s to stop using the name “Maine Black Bear” and making ice cream similar to Gifford’s trademarked flavor.

. Declare that Gifford’s is the senior user of the trademark Maine Black Bear.

. Award damages, attorneys’ fees and costs to Gifford’s.

Paul Richardson, co-owner of Richardson’s Ice Cream, was reportedly on vacation and could not be reached for comment.