A 12 per cent increase in revenue to $444 million has boosted fleet management company LeasePlan Australia's interim profit before tax by 31 per cent to $17.2 million, for the half year to June 2008.Net profit of $19.2 million for the period was more than double the $9.2 million of 2007, due to an income tax return of $2 million in 2008 compared to a $4 million expense a year earlier.Operating revenue increased 11 per cent for the period to $384 million, with finance revenue up 18 per cent to $59 million.Fleet management expenses increased 15 per cent to $236 million, with finance costs relatively well contained increasing 10 per cent to $43.5 million.LeasePlan Corporation is the controlling parent of LeasePlan Australia, in turn owned by a consortium consisting of Volkswagen Group (50 per cent), Mubadala Development Company (25 per cent) and Olayan Group (25 per cent).