Strikes in the middle of a contract are rare, but the union, which represents operators, technicians and service representatives, insisted that Bell Atlantic had committed unfair labor practices by making such changes without first bargaining with it.
Martin Whitehead, a Brussels lobbyist for the GSM Association, which represents operators, said his members opposed the new round of regulation.
About 30,000 people attended last year, said John W. Olcott, the president of the trade group, which represents operators and suppliers of private corporate aircraft.
The International Union of Operating Engineers, which represents operators of cranes, compressors and backhoes, began the strike on Saturday over management's demands for more efficient staffing levels.
Because so many students deal with classmates who are representing operators in return for a free trip, or better, the field has been classically fertile for fraud.
A spokesman for the European Telecommunications Network Operators Associationn, a Brussels group representing operators, said it would not comment until it had read the study.
Rob Jewell, chairman of the Glacier Country Tourism Group, which represents operators providing visitor services at Fox glacier and nearby Franz Josef glacier, said everyone was deeply shocked by the accident: "We're a small-knit community here.
One group dedicated to fighting the economic incursion of tribes nationally -- the Coalition Against Sales and Excise Tax Evasion -- consists of trade groups representing operators of truck stops, convenience stores and gas stations, which often compete against Indian-owned businesses.
John Richter, director of assisted living for the New York Association of Homes and Services for the Aging, which represents operators of nonprofit adult homes, said homes often sought waivers from the discharge rules for individual residents.
The GSM Association, a London organization that represents operators, said it also would await details of Mr. Nohl's study, adding that it welcomed research designed to improve GSM technology.
