Rolls-Royce recorded a net loss in the first half of 2013 compared with a profit after tax one year earlier on changes to finance costs, the maker of aircraft engines said Thursday. The British company posted a loss after tax totalling £358 million ($550 million, 416 million euros) in the six months to June 30 compared with a net profit of £1.2 billion in the first half of 2012, Rolls-Royce said in an earnings statement. Underlying pre-tax profits however surged by a third to £840 million, while revenues jumped 27 percent to £7.3 billion for the company whose engines are powering the new Airbus A350 wide-bodied planes. \"While underlying profits were up 34 percent... it is clear we have a lot more to do on cost,\" Rolls-Royce chief executive John Rishton said in the statement, adding that the company was maintaining its full-year profit estimates.