An elegantly appointed 14-room apartment at 720 Park Avenue, one of the architectural gems to emanate from the exacting toolbox of the prolific Rosario Candela in the late 1920s, sold for $23 million and was the most expensive transaction of the week, according to city records. The residence, No. 9A, had been listed at $30 million in 2011, was briefly delisted when it found no qualified takers, and returned to the market last December with a more appealing asking price of $25 million. The monthly maintenance fees are $17,504. The neo-Georgian brick-and-limestone building rises 17 stories and has 29 residences. With an impressive 80 feet of Park Avenue frontage and every room designed on a grand scale, with plaster moldings, herringbone floors and period detail intact, the Lenox Hill apartment has five bedrooms, six baths, and three fireplaces. A private landing off the elevator leads to a 30-foot primed-for-entertainment living room with Park Avenue views. John Burger of Brown Harris Stevens represented the seller, Peter A. Aron of Kings Point, N.Y., the vice president of Lafayette Enterprises, a private asset management firm. The buyer, also in finance, was Steven Tananbaum, the chief executive of Golden Tree Asset Management, and his wife, Lisa Tananbaum. Park Avenue and Mr. Burger also figured prominently in another high-end sale at yet another Candela-designed co-op. A meticulously renovated 14-into-12-room residence, No. 11B, just up the avenue at 765 Park, sold for $20,934,475; its monthly maintenance fees are $10,172. The asking price was $23 million. This residence, renovated by Albert Hadley in a classic yet modernist mode, has 5 bedrooms, 6 baths, a powder room, 4 fireplaces, 25 oversize windows, 3 exposures and a custom kitchen designed by Carlos Aparicio. The private elevator landing opens onto a 29-foot gallery that connects to a 32-foot wood-paneled corner living room with a fireplace. The formal dining room and library also have fireplaces, as does the master suite. The kitchen has soapstone counters, Wolf and Sub-Zero appliances, and sliding glass doors to a breakfast room; there is a staff suite off the kitchen. Mr. Burger of Brown Harris Stevens and Melinda Nix of Sotheby's International Realty shared the exclusive listing on behalf of the sellers, Ernesto Cruz Jr., the longtime head of Equity Capital Markets at Credit Suisse Group, and Zoe Cruz. The buyer was R. Christopher Errico, a managing director of UBS. Because of confidentiality agreements, Mr. Burger declined to supply the identity of the buyer's brokers in either Park Avenue transaction. This week, Big Ticket includes closed sales from the previous week, ending Tuesday.