The week ahead in business and economics: May 8-11

British supermarket chain Sainsbury said on Wednesday that net profits leapt almost 50 percent in the first half of its financial year, lifted by lower costs and sales growth.However, the group also warned that the trading environment would remain challenging for the rest of its 2009/2010 fiscal year a fierce recession in Britain.Net profits surged 48.2 percent to 252 million pounds (280 million euros, 422 million dollars) in the 28 weeks to October 3, compared with the equivalent period of the previous year, Sainsbury said in a results statement.