D.C. police broke up yesterday what they called a "multimillion-dollar fencing ring" that had allegedly operated a "thieves flea market" outside a Northwest plumbing supply house, recovering 11 truckloads of merchandise and arresting four men.

Merchandise was stolen from construction sites in D.C., Maryland and Virginia, and allegedly taken to a central location at the Atlantic Plumbing Supply Co., 807 V St. NW, where individuals, including contractors, "took their pick of stolen property for their business or personal use," according to Inspector Edward J. Spurlock.

The department's 2 1/2-month surveillance of a parking lot outside the company building culminated yesterday with the execution of search warrants there and at 14 other locations, including apartments, town houses and another commercial establishment.

Sgt. Donald Lyddane of the D.C. Police Repeat Offenders Project, which conducted the investigation, said police seized "refrigerators, stoves, building materials . . . tools, doors, windows, you name it." Documents filed in D.C. Superior Court stated that other merchandise handled by the ring included chandeliers, microwave ovens, dishwashers and government property.

Yesterday morning, according to police sources, undercover officers, using a truck filled with merchandise borrowed from Hecht's department store, ran their own "sale" outside Atlantic Plumbing, where about a dozen customers gathered to buy their wares.

"It looked like Filene's basement in Boston on sale day -- people elbowing and pushing each other over who was going to buy what," said one officer present. "It was like a zoo." Police used the sale "to confirm a pattern of buying and selling stolen goods at that location," according to Sgt. Carl Occhipinti.

Police said the merchandise was recovered and authorities will present evidence to a grand jury, which will conduct a further investigation.

Three men allegedly involved in the ring were arrested at Atlantic Plumbing Supply Co. and charged with trafficking in stolen property, which is a felony, police said. They were identified as Morris Battle, 64, of 1823 Wyoming Ave. NW; Ernest Lee Toye Jr., 38, of 4806 Eighth St. NE and Ronald Jonathan Owens, 32, of 5107 57th Ave., Bladensburg. According to court records, Toye and Owens were counter salesmen at Atlantic. Police described Battle as a private contractor, but court records described him as retired. The three appeared in D.C. Superior Court yesterday and were released on their own recognizance.

A fourth suspect, identified by police as Robert Donald Johnson, 45, of 2209 14th St. NE, was arrested at his home and charged with receiving stolen property, also a felony. Police sources said he was not involved in the ring, but his activities were discovered during the investigation. Police described Johnson as a self-employed landlord.

Police said the owners of Atlantic apparently were not aware of the operation. A spokesman for the company could not be reached for comment.

Spurlock said the property recovered yesterday included 14 stoves stolen from a Prince William County development of new houses and that the ring routinely operated at house, condominium and apartment construction sites as far as 40 miles outside the Beltway.

He said the merchandise, sometimes new and still in its original boxes, was left unguarded at the construction sites, from which it was stolen and taken into the city.

Spurlock said that he expects "more than a dozen" indictments during a grand jury investigation, which he expects to start in a few days.

The investigation was sparked by Montgomery County Detective Dave Senires, who notified D.C. police after a series of burglaries at construction sites in Germantown. Senires said he believed the merchandise was being transported into the District.

According to court documents, D.C. police later were told by an informant that stolen property was being sold outside Atlantic and had been "since 1977." The informant also had observed sales "as many as six times a week and sometimes two or three times a day," according to the affidavit signed by police