The Supreme Court ruled yesterday that a financially troubled businessman lost an important right under the federal bankruptcy code because he failed to disclose all of his assets as the law requires.

In a 5-to-4 decision in Marrama v. Citizens Bank of Massachusetts, the court said Robert Marrama of Gloucester, Mass., could not convert his bankruptcy case from one chapter of the code to another, as the law ordinarily allows.

The reason, the court said, stemmed from his failure to disclose a Maine vacation home placed in a trust. Marrama, who operated a flooring company, listed the value of his interest in the property as zero, according to papers in the case.

After finding out about the home, the bankruptcy trustee said he would recover the real estate for the benefit of Marrama's creditors. Marrama had attempted to convert his case from a Chapter 7 liquidation to Chapter 13, which allows a debtor to keep property and pay debts over time.

Writing for the majority, Justice John Paul Stevens said that honest debtors possess an absolute right to convert their cases to Chapter 13, but that nothing in the law limits a court's right to take away that right for "fraudulent conduct."

In dissent, Justice Samuel A. Alito Jr. said the bankruptcy code "unambiguously provides" that a debtor has a "broad right" to convert to Chapter 13. Alito said Chapter 13 contains a number of requirements that protect creditors from any bad faith by a debtor.

In Marrama's case, a bankruptcy judge denied the conversion to Chapter 13 and a bankruptcy appellate panel agreed.

Eric Brunstad, an attorney who represented the creditor in the case, Citizens Bank of Massachusetts, said that once a bankruptcy is converted from Chapter 7, the trustee is ousted and in many instances "there really is no one to take action against a fraudulent debtor."

"The statutory safeguards in Chapter 13 are not always adequate to prevent abuse," Brunstad said.