The Court of Justice of the European Union (CJEU) accepted the argument of the PRCA and Meltwater that browsing and viewing articles online does not require authorisation from the copyright holder.
PRCA director general Francis Ingham said: "We are utterly delighted that the CJEU has accepted all of our arguments against the NLA, which represents eight national newspapers.
"The Court of Justice, like the Supreme Court before it, understands that the NLA’s attempts to charge for reading online content do not just affect the PR world, but the fundamental rights of all EU citizens to browse the internet.
"This is a huge step in the right direction for the courts as they seek ways to deal with the thorny issues of internet use and copyright law. We are pleased that we have stood up for the PR industry – along with Meltwater – when everyone else rolled over."
However, David Pugh, managing director of the NLA, stressed that the result of the case had no bearing on the licences NLA Media Access issued to Meltwater and other media monitoring agencies or to those agencies' clients.
"Media monitoring agencies still require a licence to copy online content to create paid-for services for their clients and their clients still need a licence to receive those services. This ruling does not change anything in that. If you're a client of Meltwater, you still need a licence to view that content."
Pugh added: "This will only have an impact if new services are developed in future where the agencies create a portal that their clients access to view the content; if that means the end user does not need to pay a licence fee then we would seek to increase the fees paid by Meltwater and other agencies."
The judgement, delivered in the Fourth Chamber of the ECJ this morning, is the culmination of a legal challenge that started in 2010 when Meltwater, backed by the PRCA, took the NLA to a Copyright Tribunal over its Web Database Licence and Web End User Licence agreements.
There followed a four-year legal battle, in which the PRCA suffered defeats in the High Court and the Court of Appeal, before winning seven out of nine changes proposed in a final Copyright Tribunal hearing in 2012, followed by victory in the Supreme Court and now the CJEU.
Jorn Lyseggen, chief executive of Meltwater, said: "We are pleased that the European Court of Justice has stepped in to set an important precedent for internet freedom across the European Union. This ruling serves the interests of business, technology and millions of internet users and ensures protection from being accused of copyright infringement.
"Meltwater is a strong believer in copyright and a strong supporter of a sustainable, independent press. However, we are pleased that the court has interpreted the copyright law in a way that allows citizens to use the internet without fear of unintentional infringement."