Italy's Fiat (FIA.MI) car sales in Western Europe in September will increase 14.8 percent from the same month last year, to 106,100 units, the director of research group IHS Global Insight, Pierluigi Bellini, said on Monday.

The IHS Global Insight forecast refers to the EU-15 countries plus Norway and Switzerland, Bellini told Reuters.

Fiat's market share in September is expected to rise to 8 percent from 7.6 percent the previous year, he said.

The overall market is expected to grow 9.3 percent to 1.326 million vehicles.

In the first nine months of the year, Fiat car sales are seen up 2.9 percent at about 916,000 units, he said, compared with a 4.8 percent fall in the market overall to some 10.3 million units.

European car makers' association ACEA is due to release car data for September on Oct. 15. (Reporting by Stefano Rebaudo, writing by Stephen Jewkes, editing by Maureen Bavdek)