Mr. Altemose made his mark developing major projects in the suburbs, especially the Valley Forge Convention Center complex. In June 1972, his firm's building site in Valley Forge was attacked by union members, causing an estimated several hundred thousand dollars worth of damage.

Two months later, in August, Mr. Altemose was outside his bank at 15th and Chestnut Streets when he was personally attacked by union members. The attacks made national news and were the subject of a special feature on CBS's 60 Minutes.

To his fellow "open-shop" builders, Mr. Altemose was a hero, paving the way for non-union contractors to gain ground in a heavily unionized area. To those in the building trades, Altemose represented a threat to union abilities to make sure workers were paid well and had adequate benefits and safety protections.

Geoffrey Zeh, president and chief executive of the Southeast Pennsylvania chapter of Associated Building Contractors, an open-shop organization, said the events of June 1972, were significant in local and national labor history.

"I believe they also represent a bellweather where the physical violence associated with union construction activity disappeared to a significant extent," Zeh said today.

On June 5, 1972, about 1,000 members, many wearing hardhats, swarmed over a construction site in Center Square, Montgomery County, where nonunion Altemose was building the Valley Forge Sheraton Hotel.

The union members "stormed the Valley Forge site, overrunning a fence and destroying $400,000 worth of equipment and materials," according to a Pennsylvania Crime Commission report on the incident.

"The half-dozen or so local and state police were helpless in the face of the mob, and the Altemose security guards fled for their safety," the report said.

Despite the criminal charges that followed and the conviction of at least 11 of the participants, the Altemose siege remains a point of honor for many in the macho world of the building trades.

Patrick Gillespie, who heads the Philadelphia Building and Construction Trades Council, an umbrella group of construction unions, said that no one should praise Altemose, even at his passing.

"He was about destroying the standard of wages and driving them down," Gillespie said. "That was his brand of economics."

Mr. Altemose is survived by his wife, Carol Clemson; daughter, Lynn Jarrett; son, Lance; a sister and two grandchildren.

Memorial services will be held at 11 a.m. Saturday at the Cornerstone Church on Skippack Pike and Stump Hall Road in Skippack. It will be preceded by calling hours at 9 a.m.