La Ronda's buyer, Joseph D. Kestenbaum, is a high-powered private investor and entrepreneur with more than 30 years' experience in finance.

Kestenbaum, who is in his mid-50s, is president and chief executive officer of ELB Capital Management of Philadelphia and Marsh Hawk Capital Management of Plymouth Meeting.

ELB Capital manages $500 million invested in a portfolio of middle-market companies. Marsh Hawk is a direct-equity investor with $250 million of capital to invest. ELB owns 100 percent of Marsh Hawk.

Kestenbaum did not respond to a request for an interview at his Plymouth Meeting office and no one answered the door at his residence in Penn Valley.

He founded Marsh Hawk with Eric L. Blum, who started ELB Capital. The two men were partners in Unitek USA L.L.C., a service provider to the satellite, cable, and telecommunication industries that was sold to a major private-equity firm in September 2007.

Since the sale, Kestenbaum and Blum have lent a total of $34 million to Unitek to support the company's growth.

ELB's diverse portfolio includes $16 million invested in 1706 Rittenhouse Square in Center City, a luxury 31-story condominium tower featuring 29 mostly single-floor units.

The $145 million project, developed by Scannapieco Development Corp. and the Parkway Corp., will be topped off in ceremonies Thursday.

As president of Kestenbaum Group Inc. during the 1990s, Joseph Kestenbaum specialized in investments in manufacturing, service, and distribution companies.

In 1998, Kestenbaum expanded to include real estate and has sponsored and managed numerous multimillion-dollar commercial real estate investments.

He also is chairman and chief executive officer of the Kestenbaum Family Foundation, which focuses on charitable giving. He serves on the boards of Specialized Industries, Seagrave Fire Apparatus, and Half Off America - companies in which ELB has investments.

He was listed as a contributor to the Republican National Committee in 2008.

Since 1995, Kestenbaum has been married to the former Sharon Tobin, daughter of Sylvan and Frances Tobin. Sylvan Tobin is the son of Louis Tobin, one of the founders of Fishman & Tobin, the venerable Conshohocken-based clothing manufacturer.

Sylvan Tobin, who remains a consultant to the company, was a former limited partner in the Philadelphia Flyers, and his wife ran Flyers Charities for 29 years.

Sharon Kestenbaum, a 1983 graduate of the University of Pennsylvania, is active in charitable causes in the region, including the Children's Crisis Treatment Center and the Wistar Institute.

She was a contributor to the McCain-Palin Compliance Fund in 2008 and gave her occupation as executive with Bala Properties Group, listed at the same Conshohocken address as Fishman & Tobin.

The Kestenbaums are active members of Congregation Har Zion in Penn Valley. They bought their five-bedroom, four-bath, 6,400-square-foot home in Penn Valley for $516,000 in 1996.

Inquirer staff writer Bonnie L. Cook contributed to this article.