Arthur W. and William L. Zeckendorf, the developers, are in negotiations to acquire the unused development rights, known as "air rights," of Christ Church on the northwest corner of Park Avenue and 60th Street and the adjacent Grolier Club at 47 East 60th Street.

According to Carolyn L. Smith, the president of the club, which is an organization of bibliophiles, the Zeckendorfs own three low-rise buildings just to the west of the club and plan to use the air rights from the club and church to erect a 35-story residential condominium tower on the site of their low-rise buildings on the block.

She told CityRealty.com today that the club had voted Monday to approve the financial details of the sale of its available air rights that amount to about 16,000 square feet. Ms. Smith indicated that the church's congregation is expected to vote on the proposal to sell its air rights in the next few days.

She said that both the club and the church expect to receive about $430 a foot for the air rights. An article by Charles V. Bagli on the front page of today's New York Times indicated that some New York appraisers maintained that the previous "high end for the price of air hovered around $200 a square foot."

Ms. Smith said that part of the club's deal with the Zeckendorfs would provide the club with a second means of egress within the new development. She added that she understood that the deal with the church is likely to involve the availability of a Park Avenue address for the new project. She said the club will receive $7 million and that the church would get about $30 million.

The project's site is familiar territory for the Zeckendorfs as it is close to one of their other major developments, 515 Park Avenue, the tallest apartment building on the avenue.

The Zeckendorfs, whose family has historically, and legendarily, been a pioneer in real estate development in the city, are also building 15 Central Park West, a two-towered luxury condominium development, on the former site of the Mayflower Hotel.

The new tower is half a block north of the former Delmonico Hotel that has been converted by Donald Trump into Trump Park Avenue, a residential condominium project, and that building is across 59th Street from 500 Park Avenue Tower, another residential condominium tower. Other tall projects in the vicinity include the Sherry-Neteherland and Pierre Hotels on Fifth Avenue.

The Grolier Club, which is named for Jean Grolier, a 16th Century French bibliophile, erected its present quarters, which were designed by Bertram G. Goodhue, in 1917.

Christ Church was erected in 1932 and designed by Ralph Adams Cram. In their superb book, "The A.I.A. Guide to New York City, Fourth Edition," (Three Rivers Press, 2000), Elliot Willensky and Norval White said that the church was "designed to appear aged: the random limestone and brick is intended to look like a sophisticated patch job, centuries old." "Similarly," they continued, "the marble and granite columns appear to be, in the Romanesque and Byzantine manner, pillage from Roman temples. Handsome, and of impeccable taste, it is an archaeological and eclectic stage for well-to-do parishioners. Look at the mosaic ceiling, especially when lit by blue bulbs."

Attempts to reach the Zeckendorfs by phone today were unsuccessful so no details were available about how many units the new development might have and who is its architect.