City sources predict the FTSE 100 will open up 16 points from yesterday's close of 6,054, with investors focusing on an upbeat trading update from supermarket giant Sainsbury.The chain enjoyed record-breaking Christmas trading as it increased its market share in the last three months of 2012. But the firm warned the celebrations would probably not last into the new year. "We expect the challenging economic backdrop to persist, with customers looking to re-balance their household budget after the festivities and so spending cautiously in the first few months of 2013," said Chief Executive Justin King.In other company news, quality and safety services firm Intertek has purchased Tickford Test Technology, a privately-own UK vehicle engine-testing business, as it attempts to build its exposure to growing regulation within the automobile industry. The business was acquired by Intertek on December 31st 2012 from its management shareholder for £5.5m and will form part of the company's Commercial & Electrical division.Designer brand Ted Baker announced a solid rise in sales over the festive period as Chairman Robert Breare confirmed he will step down after more than 11 years in the role. David Bernstein, currently Senior Independent Non-Executive Director, will succeed Breare with immediate effect.UK economic announcements due out today include the BRC shop price index and the trade in goods and services reading, while abroad Germany is set to release its industrial production figure. Across the pond, US equities finished the day slightly off their intra-day lows ahead of the release of aluminium giant Alcoa´s quarterly results, which typically mark the start of the corporate earnings season in the US.