According to Istat, in September 2011, the index of producer prices of industrial products increased by 0.2% over the previous month and by 4.5% compared to September 2010. The prices of products sold on the domestic market registered a growth of 0.2% compared to August 2011 and by 4.7% on a trend basis. Excluding the energy sector it was recorded an increase of 0.1% in conjuncture terms and by 3.7% compared to September 2010. The prices of goods sold on the foreign market marked an increase of 0.4% over the previous month (with no variation for the euro area and +0.4% for the non-euro area) and 3.9 % compared to September 2010 (+3.5% for the euro area and +4.0% for the non-euro area). The main contribution to the growth trend of the price index of goods sold on the domestic market comes from the component relating to intermediate products (2.0 percentage points). Even with respect to the foreign market the most important contributions come from intermediate goods (1.8 and 1.5 percentage points respectively), both for the euro and non-euro area. The sector of economic activity where the trend growth of prices is more pronounced is the manufacture of coke and refined petroleum products, with an increase of 17.9% on the domestic market and 30.5% on the foreign one.