NBC is already being struck by 2,800 members of the National Association of Broadcast Employes and Technicians.
Leaders of the union, the National Association of Broadcast Employees and Technicians, said they would immediately appeal the decision to the labor board's general counsel in Washington.
The temporary workers would, however, be covered by the contract negotiated by the National Association of Broadcast Employees and Technicians.
But the National Association of Broadcast Employees and Technicians discovered NBC employees were using other gates, according to a union spokesman.
The National Association of Broadcast Employees and Technicians yesterday sent its 2,800 members a copy of the contract and strike settlement proposed by the network.
But of those, none will be American employees who belong to the biggest union at the network, the National Association of Broadcast Employees and Technicians.
The writers at NBC belong to the National Association of Broadcast Employees and Technicians.
Arthur Kent, president of the National Association of Broadcast Employees and Technicians, said, "I certainly would give that very serious consideration."
The union, Local 11 of the National Association of Broadcast Employees and Technicians, said it would strike if that happened.
"It looks like we're really heading for a strike," said John Krieger, a spokesman for the National Association of Broadcast Employees and Technicians.