More than 300,000 gallons of a sparkling Italian wine are chilling aboard a ship being detained in Baltimore harbor, while dropping temperatures threaten to turn the beverage into what one interested party callled "a giant wine popsicle."

The French ship SS Fontenoy is the pawn in a legal battle between its owners and several creditors. The Fontenoy's owners have failed to come up with the money to unload it, and the cargo must remain on board until someone raises $80,000 in unloading fees, according to Kieron Quinn, a lawyer representing the wine's importer, Banfi Inc., in Baltimore.

Banfi has been fighting freezing temperatures and trying to keep 138,000 cases of Reunite Lambrusco warm, Quinn said.

Since last week, the temperature in one of the ship's holds has dropped from 42 to 32 degrees, he said. Yesterday, Banfi ordered giant heaters, normally used to keep banana boats warm, brought in from Philadelphia to heat the holds, said Quinn, who is representing Banfi in Baltimore.

Banfi's New York City lawyer, Timothy V. Smith, said: "We're very concerned about preserving the quality of the wine. Surveyors have been checking the temperature daily. Thank God, they didn't think it was necessary to get the heaters out there until this weekend.

"We feel pretty sure it's still safe, but caution is the better part of valor," he said.

Smith said his major fear is that the $2 million worth of wine will freeze, expand and burst its bottles, though wine experts say the temperature in the holds have to slip to about 18 degrees for this to happen.

The trouble for the Fontenoy began when a New York firm that leases giant cargo containers sued the ship's owners for an unpaid debt, Quinn said.

The ship, then headed for Baltimore Harbor, "stayed out in the ocean while the owners tried to put together some cash," Quinn said.

But apparently they failed, and the ship came into the harbor about two weeks ago. As is customary under maritime law, it was seized by federal marshals on behalf of the creditors, Quinn said.

Since then, Banfi and other owners of cargo have been putting together the $80,000 in unloading fees, Quinn said, and hope to have the cargo out by Wednesday.

Banfi, however, has the only perishable cargo on board, and other troubles, besides bursting bottles, could befall their product.

At about 22 degrees, potassium tartrate, one natural component of the wine, could "crystallize" and cause tiny deposits, according to Maryland wine maker Hamilton Mowbray.

"It's not harmful to the taste, it's just a visual aspect," he said.

Though lawyer Smith maintained that the cold would not affect the wine's taste, Mowbray contended that freezing temperatures would cause "a slight flavor change."

"Ninety percent of the public would never detect the change," Mowbray said. "But, of course, the expert could tell."