Stocks are set to drift lower at the outset as the market absorbs yesterday's gloomy report from the Bank of England. City sources predict the FTSE 100 will open down 24 points from yesterday's close of 5,509. Centrica, which trades under the British Gas brand, warned that full-year earnings will be a bit lower than the market is expecting, due to the unusually warm weather experienced in recent months. "Subject to weather conditions for the remainder of the year, we continue to expect growth in full year earnings, despite significantly lower margins in our downstream residential business than in 2010," the group said.Outsourcing colossus Serco said the outcome for the current financial year should be in line with expectations, despite continuing headwinds in the UK and US. "While short-term headwinds remain, particularly those facing the US federal contracting industry, longer term developments in our markets and our strong positions are all encouraging factors. This underpins our confidence that the portfolio will sustain growth well into the future," said Serco's chief executive, Christopher Hyman.Engineering and project management services firm AMEC was another company saying trading is in line with expectations despite current macro-economic uncertainty. The oil & gas and mining sectors have been keeping the company busy, and the order book remains strong at £3.3bn at the end of October, up from £3.1bn a year earlier but down from £3.4bn at the end of June 2011.--jh