NEW YORK - A Manhattan art dealer who catered to celebrities and artists' heirs apologized Thursday for bilking about $120 million from clients to finance a once-luxurious life now unraveled into bankruptcy, illness and a struggle with drinking.

"I am deeply ashamed and sorry for my actions," Lawrence B. Salander told a judge in a husky voice after acknowledging he stole millions from tennis star John McEnroe, the estate of actor Robert De Niro's father and others.

Salander, 60, admitted swindling them for years through bogus art investment opportunities and sales of pieces he didn't own. He pleaded guilty to grand larceny and scheming to defraud, in exchange for a sentence expected to top out at a range of six to18 years in prison.

The former Manhattan gallery owner said he sold investors shares in artworks that amounted to more than 100 percent, inflated the prices backers paid to buy in and lied about having lucrative deals lined up to resell the pieces.

Meanwhile, he said he kept sale proceeds he should have given to artists' families and others who entrusted him with pieces to sell. Sometimes he used their artworks to satisfy his own debts in a life prosecutors have said was rife with such perks as private jet travel and a 66-acre country estate.

"Lawrence Salander's desire for an extravagant lifestyle turned longtime friends and trusted business colleagues into his personal piggy banks," Manhattan District Attorney Cyrus R. Vance Jr. said in a statement.

For many victims, he noted, the art held not only financial worth but personal significance as the work of their parents or grandparents.

Earl Davis, son of artist Stuart Davis, was swindled out of $15 million to $25 million after consigning 96 of his father's paintings to Salander for sale. The estate of abstract expressionist Robert De Niro Sr., the actor's father, lost about $1.25 million, Salander admitted.

Some investors in Salander's supposed art deals lost still more - about $45 million, in the case of a group called Renaissance Art Investors LLC. McEnroe was out about $2 million after Salander sold him a half-interest in a painting by the renowned abstract expressionist Arshile Gorky - a painting the tennis champion later learned was on someone else's wall, prosecutors have said.