Switzerland decides to reduce its immigration quotas.

ZURICH, Feb 9 (Reuters) - Swiss voters on Sunday narrowly approved a proposal to reintroduce immigration quotas for European Union citizens, Swiss television reported, a result that casts doubt on bilateral agreements with the EU and could anger multinational companies.

While neutral Switzerland is not an EU member state, its immigration policy is based on the free movement of people within the European bloc, as well as allowing entry to a limited number of citizens from countries outside the European community.

The vote, held 12 years after an agreement with the EU on the free movement of people came into effect, could harm an economy dependent on foreign professionals, increase bureaucracy, and threaten bilateral agreements.

In a close vote, 50,3 percent supported the so-called "Stop Mass Immigration" initiative, which also won the required majority in more than half of Switzerland's cantons or regions, Swiss television reported.

The result forces the government to turn the initiative, led by the right-wing Swiss People's Party, into law.

The result reflects growing concern among the Swiss population that immigrants are undermining the country's distinct Alpine culture and contributing to higher rents, overcrowded transport, and increased crime.

Opponents of the measure say it could exacerbate the shortage of skilled workers in Switzerland, home to Roche, Novartis, UBS, Nestlé and other multinational companies full of foreign professionals.

"Explanatory and constructive talks with the EU are urgently needed," the Swiss Bankers Association said in a message on Twitter following the result.

(Reporting by Alice Baghdjian, Albert Schmieder and Caroline Copley)