NEW YORK -- A lawsuit filed yesterday at the urging of former Philippine First Lady Imelda Marcos seeks to block the planned auctions this week at Christie's of some $10 million in antique silver and old-master paintings once owned by Marcos and her late husband, Ferdinand.

The proceeds of the sales were to be earmarked for Philippine earthquake relief efforts and agrarian reform programs, the Philippine government has said. The paintings and silver were seized by the government after Ferdinand Marcos was overthrown in February 1986.

The lawsuit, filed in Philippine Supreme Court by 23 Filipino artists, challenges the government's right to transfer to Christie's the title to the treasures, saying they are the property of the people of the Philippines.

"Mrs. Marcos makes no claim to the properties whatsoever," said James Paul Linn, her attorney. "They were given to the Filipino people and then secretly taken out of the Metropolitan Museum of Art in Manila, without any basis of law whatsoever." Linn said Marcos did not file the suit herself because as an exile, she could not travel to Manila to testify.

Teresa Roxas, spokeswoman for the Philippine presidential commission arranging the sale, said the lawsuit was no more than a publicity stunt.

"Mrs. Marcos is trying to embarrass the government, trying to affect the sale so that prices will come down," Roxas said. "You know, bad publicity may scare buyers away. It will cause more harm to the very people she's professing to love so much. We're selling silver cake baskets because people don't have rice to eat."

Roxas also said her government has already certified that the paintings and silver "are of no serviceable use" and that the National Museum has certified that the artworks "are not part of our national heritage."

The Philippine Supreme Court was to hear arguments on the case today. The sales at Christie's are scheduled for tomorrow and Friday.

Although the paintings and silver are already in New York, a Christie's spokesman says it is unlikely the auction house would go through with the sales if the ownership of the items is in dispute.

"If the Philippine government can't pass title on it, it puts Christie's in a very risky position to sell these works, and it puts anyone buying it in a bad position," said attorney Linn.

Roberta Manaker, a spokeswoman for Christie's, said the auction house is optimistic the lawsuit will fail. "We have every reason to assume the sales will proceed," she said.

Asked who the artists who filed the suit are, Linn said he had all their names "but they're not meaningful to me or to you. Mrs. Marcos caused the suit to be filed but she couldn't participate in it directly."

The attorney said the suit contains "a devastating letter" written by the government's chief auditor, Eufernio C. Domingo, last October to President Corazon Aquino, questioning the authority of the Philippine Presidential Commission of Good Government to enter into a consignment agreement with Christie's. The letter also alleges that the artworks are "historical relics and hence have cultural significance, the disposal of which is prohibited by law."

According to Linn, the auditor's letter also claims that the commission has a poor track record with Christie's in "asset disposal," and that it incurred $600,000 in expenses in a December 1987 Christie's sale of paintings that grossed $600,000. In that sale, a still-life painting by French artist Henri Fantin-Latour sold for a record $440,000.

"I can show you the deposit slips into the account of the national treasury of all the money that was raised from the auction at Christie's," responded Roxas. "That allegation is completely unfounded. Those questions by the auditor have all been settled since October."

She said her commission "is fully prepared to answer all allegations and will do so at the Supreme Court tomorrow."

Among the 71 old-master paintings consigned by the Philippines government are works by the Renaissance master Raphael and the Sienese painters Segna Di Bonaventura and Bernardino Fungai. Before their overthrow, the Marcoses exhibited the art as part of the Marcos Foundation in the Metropolitan Museum of Art in Manila. Mrs. Marcos founded the museum in 1976.

The suit does not address the 22 paintings, formerly held by Adnan Khashoggi, a close associate of the Marcoses, that are being sold Friday by Christie's with the other paintings.

Roxas confirmed that Christie's has advanced 70 percent of the low estimate of the paintings and silver -- between $5 million and $6 million -- to the government, calling it "a generous gesture of goodwill." Asked what would happen to the advance if the court decided to stop the sale, Roxas said, "Theoretically, if the impossible happened, all we'd have to do is give the money back."