Three banks and the federal government have asked a federal judge to declare real estate investor Dominic F. Antonelli Jr. and his wife, Judith, bankrupt and sell their personal holdings for the benefit of their creditors.

The action initiated what could become the biggest bankruptcy of the Washington area's real estate bust, lawyers said.

It appeared to derail a proposed out-of-court settlement between the Antonellis and other creditors that would have extricated the Antonellis from $548.4 million of loan guarantees while allowing them to recoup as much as $17.5 million.

The involuntary bankruptcy petition was filed Thursday by Riggs National Bank, First American Bank, Chase Manhattan Bank and the federal agencies that took over two failed lenders, the National Bank of Washington and Baltimore Federal Financial.

Since last summer, the Antonellis have been trying to restructure hundreds of millions of dollars of delinquent loans through private negotiations with their lenders. Most of the Antonellis' 36 lenders, including American Security, Sovran and Crestar banks, had endorsed a plan in which Antonelli would sell almost all his holdings over a period of years and they would share the proceeds.

The lenders asking a bankruptcy court to take control of the liquidation concluded "that they were going to be left on the short end" of the out-of-court deal, in the words of one source close to the creditors.

The out-of-court liquidation plan would have resulted in the Antonellis and some creditors "receiving more for themselves than they would otherwise be entitled to in a court-administered liquidation process," said spokesman Alan Whitney of the Federal Deposit Insurance Corp., which joined the bankruptcy petition as receiver for the defunct National Bank of Washington.

The plan would have allowed the Antonellis to retain interests in their properties and earn fees for selling them. It also promised the Antonellis annual lifetime payments of $300,000 each. In a suit last year seeking to block the private liquidation, Chase Manhattan said lenders who refused to go along with that plan would receive nothing from the Antonellis.

The Antonellis' lawyer, Roger Frankel, yesterday said they had not decided what they would do about the involuntary bankruptcy petition. They have about three weeks to file a response. Under the bankruptcy code, they have the right to pursue a court-administered Chapter 11 reorganization of their debts, instead of the liquidation.

"We are very disappointed that a very small minority of the banks that are creditors here have sought to upset the out-of-court workout that the vast majority of the banks have gone along with," said Frankel, of the firm Arent, Fox, Kintner, Plotkin & Kahn.

Arnold & Porter lawyer Richard P. Schifter, who represents a group of creditors that favored the out-of-court settlement, said, "It's our expectation that a bankruptcy proceeding will go forward." But Schifter said it is still possible that, under a court's supervision, the Antonellis' debts could be restructured along the lines of the proposed liquidation.

Many bankers had favored an out-of-court solution for two basic reasons: They feared a bankruptcy could be long and costly, and they believed they could recoup more money from Antonelli's vast collection of office buildings, hotels, undeveloped land and other real estate if they sold the properties gradually and privately.

The involuntary bankruptcy petition seeks payment of $3.7 million to Riggs, $6 million to First American, $8.8 million to the FDIC as receiver for National Bank of Washington, $4.8 million to the Resolution Trust Corp. as receiver for Baltimore Federal and $50.8 million to Chase. The Antonellis have interests in more than 170 partnerships and corporations. Altogether, the real estate projects in which they hold a stake are in debt by about $1 billion, although they are only responsible for a portion of the debt.

Dominic Antonelli, now in his late sixties, began his career as a carhop and built one of the area's biggest parking garage companies. The chairman of Parking Management Inc. amassed extensive property holdings and developed downtown Washington office buildings along the way. A 100-foot yacht and a 22-acre Potomac estate are testaments to his success.

His troubles stem mainly from his decision to bankroll several other developers during the mid- and late 1980s. When their highly speculative real estate joint ventures faltered, Antonelli's loan guarantees left him responsible for a mountain of debt.

Antonelli is one of many Washington real estate developers trying to restructure troubled loans. Several others, including Conrad Cafritz, having been trying to negotiate similar "pool" arrangements with large groups of creditors instead of seeking protection under the bankruptcy code.

Lawyers who specialize in debt negotiations said the breakdown of Antonelli's effort could herald an unraveling of other settlements still in the works.

Staff writer Veronica T. Jennings contributed to this report.