A partnership of the Oliver Carr Co., Washington's biggest real estate developer, is past due on a $27 million loan on half a block of downtown land, sources said yesterday.

The full amount of the loan from American Security Bank has been due since June 30, members of the partnership said. Carr has asked for a one-year extension of the loan, but the bank has refused to grant it and recently stepped up pressure on the partnership to pay, sources said.

The Carr Co. and its investors are weighing the possibility of seeking bankruptcy protection for the partnership, sources said. But the company is concerned that a bankruptcy filing could cause other problems, according to one partner.

"It would buy them some time, but it would put a cloud over the whole company," said Peter Klock, a Connecticut lawyer and limited partner.

In another sign of growing strains on the Carr Co., 22 of its 139 employees were told this week that they would be laid off over the next six months because new development has ground to a virtual halt.

A Carr partnership called Freedom Hill Farm Associates bought the land bounded by 11th, E and F streets NW piece by piece in the mid-1980s, planning to put up an office building and movie theaters. At the time, city officials said the theaters were important because they would bring more people downtown. Several local establishments that had been there for years were forced out to make way for the construction.

However, the development has been delayed by the glut of downtown office space, tighter credit for construction and lack of a major tenant. Today, the site is a collection of vacant, boarded-up storefronts.

Carr Co. Chairman Oliver T. Carr Jr., who founded the development firm in 1962, was a member of the board of directors of American Security Bank and its parent company, MNC Financial Inc., until he resigned in October. Carr and various Carr partnerships have loans of more than $120 million from American Security and Maryland National Bank, another MNC subsidiary, sources said. The developer is negotiating to get extensions, interest rate reductions and other concessions on $50 million to $75 million of those loans, sources said.

In addition, a Carr partnership that owns land in Alexandria is past due on a loan from another bank, one source said.

Carr Co. President Robert O. Carr, Oliver Carr's son, declined to comment yesterday on his company's finances. "I don't think it's appropriate for me to discuss the private business affairs of that or any other partnership," he said.

In October, Robert Carr said, "Suffice it to say that we're current on all our loan obligations without exception."

Partners said that the partnership has continued to make interest payments on the loan since it came due last June. Four times over the last year the Carr Co. has called on its investors to put up additional cash to meet interest and other expenses on the 11th Street project, known as Lincoln Place. The cash calls were intended to raise about $6.5 million, but some partners did not contribute, sources said.

One of Carr's partners in the Lincoln Place venture is builder A. James Clark, who is a member of the board of directors of MNC and its American Security Bank subsidiary, and MNC's second biggest shareholder.

In his dual role as a director of MNC and owner of a 16 percent stake in Lincoln Place, a project with a problem loan, Clark could find himself in an awkward position, banking sources said.

Spokesmen for Clark and MNC declined comment on this issue.

Although the loan on the project was due June 30, American Security Bank "just let it ride," in the words of one limited partner.

Now the bank, under pressure from federal regulators, is turning up the heat. "The bank is bringing it to a head," said the partner. "We're down to the closing minutes."

However, another source close to negotiations said the bank has given the partnership no specific deadline for paying the loan.

Lawyers for Carr and for the partnership have been negotiating with the bank, according to one source, and have proposed that the bank give the partnership time to sell the land or find a joint-venture partner to develop it.

The partnership has asked the bank for a forbearance period of about a year -- a time period sources said the bank was unwilling to consider.

At a recent meeting of the partnership, Carr was represented by a bankruptcy attorney, while the partnership had a separate attorney because the interests of the Carr Co. and the limited partners may be at odds.

As general partner, the Carr Co. is liable for the full amount of the loan, and Oliver Carr personally guaranteed the loan, sources said.

That makes negotiating a deal that limits liability a priority for Carr and the firm, sources said.

But the dozens of limited partners who together have invested millions of dollars in the project are most concerned about preserving their investment, partners said.

The investors include great grandchildren of Anson Mills, who was in business with Oliver Carr's grandfather around the turn of the century.

One partner urged the Carr Co. to sell the land about a year ago, sources said.

At the time, Carr officials told investors in the project that the company's decision to hold on to the land was not influenced by the prospect that the firm could earn several million dollars in fees if Carr develops it.