The five-year transition period is standard for new members, the ministry has said, explaining that Slovenian researchers and companies will immediately have full access to all of CERN's programmes and infrastructure.

CERN, established in 1954, is the world's leading particle physics laboratory and an elite scientific institution that frequently produces new discoveries and has helped spur the development of a range of new technologies.

The ministry said that the participation of Slovenian scientists in CERN went back a long way. Yugoslavia was one of its 12 founding countries, but left the organisation in 1961.

Ties were revived in 1989, when CERN signed a cooperation agreement with the Jožef Stefan Institute, one of Slovenia's leading research institutions.

In 1991, the first democratically elected government signed an agreement with CERN which has been the formal basis for the participation of Slovenian scientists.

While efforts for membership were announced several times in recent years, today's signing is the result of a process started by the government last April.

The ministry has stressed that CERN membership will simplify and expand the activities of Slovenian researchers, especially in experimental physics, while it also remains an important technological and economic motive.

It will secure full access for the Slovenian industry to CERN's orders and allow a foray into demanding markets of knowledge-based products.

The starting membership fee is around 930,000 euros and gradually grows until full membership, which costs around three million euros a year.