American Realty Trust of Arlington warned yesterday that it may not be able to pay back $3.5 million of borrowings that come due next Thursday.

The problem-plagued real estate company also announced it lost $1.6 million in the quarter ended Dec. 31.

The company blamed the loss on a $2 million judgment against it in a lawsuit filed by Chase Manhattan Bank, which had accused American Realty of fraud.

In a terse announcement, American Realty said it "does not presently anticipate having sufficient cash on hand" to meet the $3.5 million it owes on subordinated debentures that fall due March 15.

Last week American Realty and its president, Thomas Broyhill, were sued for $33.5 million by Joel T. Broyhill, a former congressman and cousin of the company president. That lawsuit accused the company and its officers of withholding information from investors.

Similar charges have been raised in a Securities and Exchange Commission complaint against the company, which is still pending.

Several years ago American Realty defaulted on another debenture issue. It was not clear yesterday how a second default would affect investors in the firm or continued operations of the company.

"Various methods of securing the funds needed to redeem the debentures including sale of assets or refinancing of debt are being pursued," the company's announcement said. "No assurance can be given that these efforts will be successful."

American Realty's $1.6 million loss in the first quarter contrasted with a profit of $864,000 (39 cents per share) in the same period a year ago. A year earlier the company also claimed a tax loss credit of $412,000 that boosted earnings to $1.2 million (58 cents).

The company said it recently sold a property in Charlotte, N.C., for $850,000 and made a $364,000 profit, which will be reported in the next quarter.

A spokesman said negotiations to sell other assets are underway, but he declined to specify which of American Realty's investments might be sold.

The debentures that are due next week paid 9 1/2 percent interest.

Organized as a real estate investment trust (REIT) American Realty lost the tax advantage of that status when it began managing as well as owning property.

The company ran into financial problems during the recession of 1974, then hit legal difficulties when stockholders and business associates claimed American Realty management had mislead them about the company's financial status.