A union representative said about 70 percent of workers at Fiat's historic Mirafiori plant in its hometown of Turin took part in the stoppage but the automaker put the figure at about 20 percent.
Fiat said the plant was still operating, but at a lower level of activity.
Neither the automaker nor the union representative, Giorgio Airaudo of the FIOM-CGIL union, could provide details of the effect of the strike on Fiat plants elsewhere in the country.
The strike, which has affected Piaggio and other manufacturers, is the first show of force since the national labor contract for the sector expired in June.
Unions have been negotiating its renewal with employers but have yet to reach an agreement.
The unions are seeking a rise of 117 euros per month, while the employers have offered 60 euros.









