The 69-year-old widow of the deposed dictator Ferdinand Marcos sat in at a Supreme Court hearing as her lawyer argued for her acquittal on a 1993 graft case, for which the court last January sentenced her to between nine and 12 years in prison.

Wearing an old rose dress, pearl earrings and four-inch high stiletto shoes, she fidgeted with a rosary and occasionally dug into her handbag for paper towels to wipe her face as she sat on the front row of the gallery.

She refused later to discuss the case with journalists, referring queries to her lawyer, as ''he knows best.''

But Mrs. Marcos, who is set to celebrate her late husband's 81st birth anniversary today, added: ''I am very optimistic.''

A special court had sentenced Mrs. Marcos, a former member of her late husband's Cabinet, to up to 24 years in prison for approving the lease of a property of the Light Rail Transit Authority to the Philippine General Hospital Foundation Inc. (PGHFI), which she also headed at what prosecutors considered to be below market rates.

Justices Artemio Panganiban and Flerida Ruth-Romero said this was a clear case of conflict of interest. ''(Mrs. Marcos) cannot be both lessor and lessee,'' Romero said.

The court said PGHFI then turned around and subleased the 7,340-sq. m. lot in Pasay City to another corporation for seven times the original lease, depriving the government of P180 million in potential rental fees.

The Supreme Court in January shortened her jail term and acquitted her convicted co-conspirator, former transportation minister Jose Dans.

She has been free on bail as her lawyers petitioned the higher court to overturn its verdict.

If the court affirms its decision she would be left with no choice but to serve the prison sentence.

Her chief lawyer, Estelito Mendoza, yesterday argued for her acquittal, saying the government's case rested only on documentary evidence which he asserted did not constitute ''sufficient proof'' for the guilty verdict.

These pieces of evidence now had ''no relevance to the case'' since the court had already acquitted her co-accused, Mendoza added.

He also argued that the state had failed to present proof that his client had attended the board meetings at which the government agency decided to lease the property.

Solicitor General Ricardo Galvez, maintained that the state's failure to establish proof of conspiracy did not get Mrs. Marcos off the hook.

The Supreme Court gave both Galvez and Mendoza 10 days to submit their position papers.

It is expected to come out with a decision by October before Justice Florenz Regalado retires.

Her legal battle is proceeding amid a parallel battle among several groups of claimants to her late husband's estate, valued by some experts at up to $10 billion.

The government argues the bulk was stolen from the national treasury during the Marcos family's 20-year rule, but victims of human rights violations during that era are pressing home a US court ruling which awarded them $2 billion in damages.

Two sets of lawyers for the 10,000 people victims represented in the class suit are also quarrelling with each other, while communist guerrillas want the estate to form part of a political settlement to their 29-year rebellion.

President Estrada on Wednesday said he wanted all sequestered assets of the Marcoses and their business allies sold off in a year as he received P1.1 billion in proceeds from the sale of assets surrendered by Marcos cronies.

The previous administration of Fidel Ramos had said P31 billion had been recovered so far, but none through the courts.

The Swiss Supreme Court, meanwhile, has caused the transfer of about $570 million in Marcos bank accounts to an escrow account in the Philippine National Bank to await a court ruling here on its legal ownership.

Mr. Estrada also described as ''too small'' a reported $150 million offer by Mrs. Marcos to settle the cases against the estate.

The President's spokesperson Fernando Barican, however, told reporters yesterday that Mrs. Marcos had called him up late Wednesday to deny that she never made such an offer.

''No comment. My cases are under litigation,'' she told reporters Thursday.

With reports from AFP and Donna S. Cueto