Global commodities trader Trafigura has raised its stake in Italian refiner Saras to 12.46% from 5.23%, the companies said on Friday, strengthening Trafigura's foothold over Mediterranean oil flows. The move comes a week after Russia's Lukoil concluded the sale of its large Sicilian refinery, ISAB, to an Israeli-backed company in turn supported by Trafigura for oil supplies. Saras, controlled by the Moratti family, operates the 300,000-barrel-per-day Sarroch refinery in Sardinia, one of the biggest plants in the region.