REAL ESTATE > Time Warner Center

NYTIMES.COM: The last apartment has been sold at the Time Warner Center, a half-floor penthouse on the 77th floor of the north building that went for $16,950,000.

THE Related Companies sold the last remaining apartment at Time Warner Center in the final week of March, logging total sales in the two-building complex of more than $1.1 billion, according to David J. Wine, the vice chairman of Related.

The last apartment to sell was a half-floor penthouse on the 77th floor of the north building, which contains the Mandarin Oriental Hotel.

It sold for $16.95 million, Mr. Wine said, but he refused to identify the buyer. He said that all but three units in the complex have closed, and the final three, including the last to go to contract, are expected to close by the end of the month.

The average price per square foot in the building was about $2,500, Mr. Wine said. The buildings were designed with a total of 201 units, but a small number have since been combined to create larger apartments.

The buildings, overlooking Central Park at Columbus Circle, have attracted a handful of billionaires, including at least two who have snapped up full-floor penthouses in recent weeks.

Last month, J. Joe Ricketts, the founder of Ameritrade, the online stock brokerage company, paid $29.2 million for the 78th floor of the north tower. The deed for the apartment was filed with the city on March 31.

Mr. Ricketts, whose son Peter is running in the Republican primary for a United States Senate seat in Nebraska, is No. 292 on the Forbes list of the world's billionaires. The magazine estimated his family fortune at $2.5 billion. An Ameritrade spokeswoman said that Mr. Ricketts does not speak with reporters.

Thomas M. Siebel has bought the 79th floor of the south tower for about $28 million. Mr. Siebel is the founder of Siebel Systems, a software company, which was sold last year to Oracle for $5.8 billion.

Mr. Siebel is No. 486 on the Forbes list, with an estimated net worth of $1.6 billion. Mr. Siebel's broker, Dolly Lenz of Prudential Douglas Elliman, said she could not discuss the deal.

Other billionaires who have bought more modest apartments in the building include John W. Kluge, No. 52 on the Forbes list with an estimated net worth of $9 billion, and Jon L. Stryker, heir to a medical equipment fortune, ranked by Forbes at No. 428, with a net worth of $1.8 billion.

Condos at the Time Warner Center went on sale just before the terrorist attacks in 2001. The complex suffered through slow sales as the city recovered, but the condos began to move the next year, and about 85 percent had been sold by the end of 2004.

The complex still has the most expensive residence in Manhattan: two floors of raw space in the south building that David Martinez, the Mexican-born financier, bought for $54.7 million. Mr. Martinez is still fitting out that space, at a cost of millions more.