The owners of Georgetown Park have sold 70 percent of their interest in the 100-store shopping mall to the American Telephone & Telegraph pension fund for $48 million to pay off construction loans on the property.

AT&T also has brought in an arm of Coldwell Banker, a nationwide real estate firm, to manage the mall, located on M Street NW in the heart of Georgetown. Coldwell Banker has signed a long-term contract with the Western Development Co., some of whose officials were among the mall's original owners, to assist in the management.

"We're very pleased," said Western President Herbert S. Miller. "We've achieved what we think is an excellent business arrangement."

Robert Stinson, a senior official with the Donohoe Co., the other major original owner, echoed Miller. "We're very happy with the financing," he said.

In bringing in an equity partner, the original Georgetown Park owners are following a trend begun in the mid-70s when it became necessary to sell some ownership in an office building or retail project to large insurance companies or pension funds in return for permanent financing, rather than to seek traditional mortgages, which have become economically unfeasible because of high interest rates.

In such deals, Washington developers usually have given up about 50 percent of their ownership in return for a below-interest-rate mortgage, according to several knowledgeable real estate sources. Miller said the original partners in Georgetown Park sold off 70 percent because "we felt it was best to have no debt" on the mall.

Before the AT&T purchase, Miller; Richard Kramer, another Western official; and the Donohoe Co., owned more than 90 percent of Georgetown Park, which opened last September. Under the new partnership agreement, a group of Western officials, including Miller and Kramer, and the Donohoe Co. own nearly 30 percent.

The AT&T purchase involved only the shopping mall. The condominiums above it are still owned by officials at Western and the Donohoe Co.

Joshua Brown, who handled the transaction for Coldwell Banker and AT&T, said the project was a good investment because "it is one of the premiere retail specialty sites . . . and has a tremendous future for appreciation and cash value."

A spokesman for AT&T said the communications giant, which controls the nation's largest pension fund, does not comment on its business arrangements.

When Western, Donohoe and the Kramer family trust, the third original partner, started looking for permanent financing more than a year ago, they hired Coldwell Banker, and were willing to give up more than half of the ownership in the retail/residential complex for $54 million in financing.

According to documents filed with the D.C. Recorder of Deeds, the original partners borrowed more than $54 million from the Bank of New York to build the mall and a portion of the condominiums.

As part of the sale to AT&T, the original partners paid the Bank of New York $39.1 million in principal and interest payments. Participants in the transaction said the remaining $8 million was used to pay legal, engineering and settlement fees, some construction fees owed to Donohoe, who built the mall, and allowances to some of the mall tenants who were promised some of their expenses but never received them.

When asked if either Western or Donohue had made a profit on the sale, Stinson said that "no one is walking way with any money." Miller declined to comment.

The Western officials and Donohoe still owe $16.6 million on the condominiums, according to the documents filed in the sale. Miller said the first 35 had been sold, half of the 29 units in the second phase were sold and the first 33 units in the final phase would be marketed in late August and range in price from $120,000 to $225,000.

As collateral for these mortgages, both the Western officials and Donohoe have pledged their share of the cash flow from the mall. In addition Western pledged its share of the cash flow from one of its downtown office buildings and Donohoe pledged half its share of the cash from the Holiday Inn at 2101 Wisconsin Ave. NW, according to documents filed with the sale.

The Coldwell Banker Commercial Group, the real estate arm of Sears, Roebuck, which now owns Coldwell Banker, has become the managing partner of the new partnership at the insistence of AT&T. Coldwell has signed a long-term contract with Western Development to manage the day-to-day operations of the mall but "all the decisions are left to us," Brown said.

Brown said AT&T's interest could increase to 90 percent in the next three to four years if the center's profitability diminishes.

A spokesman said AT&T's pension fund totals $35 billion, of which five percent is invested in real estate.