Fiat's Italian sales rose 9.5% in June from a year ago, about triple the overall growth in the automaker's key market, but its market share shrank from May, according to Reuters.

Fiat, which includes the Alfa Romeo and Lancia brands, has launched new models over the past year in a bid to protect its once-dominant share of a home market under assault from foreign rivals, the report said, noting that the country's largest industrial group again struggled with competition, especially from the Japanese and Korean manufacturers which produce many of the small, cheap models that have traditionally been Fiat's bread and butter.

Reuters said Fiat's market share shrank to 26.6% from 27.7% in May but its year-on-year sales of 52,230 cars outpaced the market, which grew 3.3% to 196,300 units.

Fiat brand sales rose 9.4%, Lancia climbed 16.0%, and the sporty Alfa Romeo brand increased 3.4%, the report added.

The fastest growing foreign brands included Hyundai and Kia, with year-on-year sales up 17.6% and 43% respectively, and Mazda, up 40%, Reuters noted.