A strong showing on Wall Street yesterday has given renewed heart to London, where the top-share index is set to open around 50 points up from yesterday's close of 5,102. Bikes and car parts seller Halfords was thankful for its recently acquired Autocentres business, which notched up a 3.1% year-on-year increase in like-for-like (LFL) sales in the 13 weeks to 30 September, offseting a 2.8% slide in LFL sales on the Retail side of the business. Full year gross margin guidance of at least one percentage point year-on-year decline and operating cost guidance remain unchanged. Group profit before tax for the first half is expected to be in the range of £53 - £55 million.Snacks seller Greggs said LFL sales were up 0.8% in the 13 weeks to 1 October, the group's third quarter. This represents a pick-up in the rate of growth from 0.4% in the first half of the group's financial year. "We remain confident in the prospects for the group and our expectations for the year are unchanged," the trading statement said.Mark Armour, chief financial officer at business publisher Reed Elsevier, is to retire from the company at the end of 2012. A search for a successor has been kicked off.--jh