Cross-Channel train operator Eurostar said Wednesday its sales rose four percent in the first six months of the year to £421 million (481 million euros, $678 million) compared with the first half of 2010. The company, which operates trains through the Channel tunnel connecting Britain with France, said passenger numbers increased by three percent to 4.7 million, aided by growth in business and leisure travel. \"This year-on-year growth is particularly strong given that in the first half of 2010 Eurostar benefited from increased sales revenues resulting from the ash cloud disruption, during which it ran 70 extra trains and carried 100,000 extra passengers,\" the company said in a statement. \"Excluding the positive impact of the ash cloud disruption on the 2010 figures, underlying first half 2011 sales revenues in fact grew by 12 percent in comparison with the same period last year.\" With planes grounded last year due to the Icelandic ash cloud eruption, travellers on both sides of the Channel increasingly used Eurostar to travel between London and mainland Europe.