The union is supporting push, which is pushing for journalists to retain copyright and moral rights over work they produce, as well as fair pay.
The campaign is being led by the International Federation of Journalists (IFJ) and the European Federation of Journalists (EFJ).
The NUJ’s involvement in the campaign comes ahead of World Copyright Day, which is marked on 23 April.
John Toner, NUJ freelance national organiser said: “We welcome this initiative, and congratulate the IFJ and EFJ for making the issue a priority.
“For many years the NUJ has placed the question of unfair contracts at the heart of our campaigning and lobbying, as it is a matter of great concern.
“We will continue to campaign at both national and international level for the rights of journalists to retain their copyright and moral rights, and for the right to equitable remuneration for the work they create.”
A statement on the IFJ’s website reads: “The growing trend among media organisations to use right-grabbing contracts has become a matter of great concern for the International and the European Federation of Journalists (IFJ/EFJ).
“As a result, the IFJ/EFJ have launched a European wide campaign against right-grabbing contracts and demanding fair payments to journalists.”