Online sales have boosted the performance of high street retailer Marks & Spencer (M&S) in trading statement for the second quarter of 2009.M&S Direct, the online retail arm saw its sales increase by a third, up 30 per cent. The international division also performed well with sales increasing by 9.6 per cent.Like-for-like sales in its home market, the UK, fell by 0.5 per cent for the second quarter which ended in September. Overall the company reported sales growth of 2.7 per cent and total UK sales increased by 1.9 per cent."Whilst there is more visibility in the marketplace and consumers appear more confident, we continue to be cautious about the outlook," said chief executive Sir Stuart Rose. "We expect 2010 to be a tough year and we will continue to run the business accordingly," he said.Online only rival to M&S Asos has seen a 50 per cent increase in its sales, it reported today in a statement ahead of its AGM. Sales in the six months ending in September increased by 47 per cent, and like M&S it saw overseas sales increase.