The Landmarks Preservation Commission approved yesterday by a vote of 7 to 1 the third revised design for an addition to the former Parke-Bernet Galleries building on the west side of Madison Avenue between 76th and 77th Streets.

The addition is planned by Aby Rosen, the owner of the Seagram Building and Lever House, both on Park Avenue and two of the city's most important icons of post-war modern architecture. It has been designed by Sir Norman Foster, whose original scheme was a 22-story, reflective-glass, double-cylindrical addition at the north end of the five-story limestone-clad existing building that was designed by Walker & Poor in 1950 for the Parke-Bernet auction house that was later taken over by Sotheby's and relocated to 72nd Street and York Avenue to the dismay of many art collectors. That design would have created a large rooftop sculpture garden and the tower addition would have had 33 residential condominium apartments but it was rejected by the commission in 2007.

The developer submitted a substantially downsized, bronze-colored redesign more than a year ago that called for five-additional floors across the top of the existing building with operable shutters and a total of 18 residential condominiums.

Both plans were strenuously attacked by some neighbors concerned about losing their Central Park vistas and by some preservation groups. The initial Foster plan would have block many south views from the Mark Hotel just across 77th Street, then undergoing renovation, and from the considerably taller Hotel Carlyle just across the avenue.

The latest revision is one-story lower in height and the number of louvers on the aluminum facade of the addition has been significantly reduced and the glass facade behind them pushed back two more feet to four feet.

Finally, the corners of the addition have been rounded off. Mr. Rosen reaffirmed his commitment to restore the original building by transforming its fifth floor back into a tree-lined terrace.

In an article yesterday by Matt Chaban at Architecture Week, commission chair Robert Tierney was quoted as stating that "this is vastly improved, strikingly contemporary," adding that "Together you'll see them as separate but also part of an ensemble."

Commissioner Margery Perlmutter, the article continued, said that the new changes "clarified the distinction of the original building, which is opaque and heavy and stone, and the addition, which is now light and airy," adding that "it creates much more transparency, making the building all the lighter."

According to the article, "Roberta Brandes Gratz, the lone dissenting vote, acknowledged that the designs were not bad, but said that nothing as large as the Parke-Bernet Building should be built atop it," adding that she still considered the addition "too massive."

In a statement, Mr. Rosen said he was "extremely grateful for the opportunity to demonstrate that you can build with distinction in an historic district if you respond responsibly and work collaboratively with the landmarks commission." "The commissioners' vote today demonstrates their confidence that our dedication to architectural integrity and the highest quality of materials will produce an exemplary result for the neighborhood and for the city," Mr. Rosen declared.

Whereas the first design did not comply with existing zoning and building regulations, the subsequent lower revisions did and only required approval from the landmarks commission because it falls within an historic district.