KARLSRUHE (Reuters) - A law to curb the strike power of smaller trade unions in Germany is mostly compatible with the constitution although some amendments are necessary, the country's top court ruled on Tuesday.
Berlin introduced the law in 2015 after a series of strikes by smaller unions paralyzed air and train travel in Germany, even though other unions within firms such as Deutsche Bahn [DBN.UL] and Lufthansa had already agreed pay deals.
The law applies to companies whose employees are represented by different unions and means that only the union with the largest number of employees can agree pay deals with company management.
The court in Karlsruhe said that the law could remain in place, but amendments had to be made to ensure that larger unions were taking into account the interests of smaller unions.
The challenge was brought by airline unions Vereinigung Cockpit and UFO, doctors' union Marburger Bund, as well as major union Verdi.
UFO had said the law contravened Germany's written constitution because it gives only larger unions the right to agree collective labor agreements, meaning that strikes by smaller unions could be ruled as unlawful and open them up to damages.
German labor minister Andrea Nahles, from the SPD social democrats, had argued that the aim of the law was for unions to work together on pay demands.
(Reporting by Ursula Knapp and Peter Maushagen; Writing by Victoria Bryan, editing by Louise Heavens)