A famed trader of rare and exotic jewels, Frederick Leighton, has seen better days.

Than yesterday, for example.

On the morning his high-end company pleaded guilty to sidestepping sales taxes for its clientele of glitterati and agreed to pay more than $1 million in restitution and fines, burglars ransacked his shop at 773 Madison Ave. and absconded with more than $500,000 in vintage, Art Deco style tiaras and a collection of antique hair combs.

According to police, the store reported that around 2:30 a.m. the burglars smashed through the front door, sending shards of glass flying out onto Madison. The tiara thieves then smashed into one of the store’s display cases, its “vitrine,” workers at the store said, and made away with more than 20 antiques, including jeweled lipstick holders, compacts for face powder, and a host of jewel-encrusted tiaras dating from the 19th century to the 1950s.

After snatching the jewels, the suspects fled south down Madison Avenue, police said.

“The question that arises,” Mr. Leighton said in a statement yesterday, “is where these ‘tiara thieves’ will sell their precious loot.”

“There are few jewelers who have an interest in carrying these unusual pieces,” Mr. Leighton said. “Very few people walk into a jewelry store looking for a vintage tiara or antique hair ornaments. They are very unique jewels that require a very special and discerning clientele. They are often worn by socialite brides or sparkle on the red carpet at the Oscars.”

The theft comes a month after a daytime heist at Adam Williams Fine Art, a nearby gallery, where two burglars snatched a 19th-century painting valued at $1 million. One theory, according to detectives investigating that case, was that the thieves had not intended to steal such a pricey piece of art but were entranced by the 1850s painting’s half-nude woman and harem-like scene.

Mr. Leighton, who for more than 35 years has specialized in exotic 19thand 20th-century pieces, is known for his roster of celebrity clients – such as Sarah Jessica Parker, Nicole Kidman, and Catherine Zeta-Jones – who sport jewels that he lends them to wear at highly publicized, red-carpet affairs like the Golden Globes and the Oscars.

Mr. Leighton’s store also became the target of an investigation by Manhattan District Attorney Robert Morgenthau, whose prosecutors have been able to recoup more than $29 million in unpaid sales taxes since they began investigating a host of high-end art and jewelry transactions in early 2002. The continuing investigation, which has produced guilty pleas and fines paid from 12 other luxury art dealers, initially began as part of Mr. Morgenthau’s probe of the lavish purchases made by the former chief executive of Tyco, Dennis Kozlowski.

According to yesterday’s guilty plea, which pins two felony counts on Mr. Leighton’s corporate entity, Fred Leighton Limited, employees at the jewelry store allowed customers to walk out with their purchases in hand but later created the impression that the customers had shipped the purchases out of state, eluding New York sales taxes.

Over a two-year period, according to yesterday’s guilty plea, the store allowed one customer to take home more than $1.3 million in jewels, including a pair of diamond platinum bracelets, an emerald and yellow gold ring, and a gold and diamond bracelet, without charging tax, and then fraudulent shipping records were created, according to court documents, creating the impression the luxury goods were sent to a second residence in Florida.

Other purchases that customers took with them from the Madison Avenue storefront that were never shipped to the designated locations out of state, prosecutors said, included a collection of 19th-century diamond necklaces, valued at $1.4 million, along with a diamond Cartier watch and cufflinks ($68,500), and a 120-carat diamond necklace ($335,000).

A spokeswoman for Fred Leighton Limited, Rebecca Selva, said the store was satisfied with the plea deal.

“We’re pleased to put this matter behind us,” she said in a statement, “and move forward with our business of purveying exquisite jewels.”

After all, Ms. Selva noted, the Golden Globe awards in Los Angeles are less than two weeks away.