With the Dow Jones suffering a triple digit fall in the US last night, traders' screens are expected to be mostly red when the market opens. City sources said the top-share index is expected to open almost 50 points down from last night's close of 5,929.Thomas Cook's third quarter results will miss expectations as the turmoil in the Arab world and economic weakness in the UK take its toll on the travel operator. The firm said its French operations have been hit particularly hard by the political unrest in countries such as Egypt, Tunisia and Morocco.Oil outfit Premier Oil moved to assure the market about production targets saying it predicts a sharply increased production rate of around 60,000 barrels of oil equivalent per day by the end of the year, as its Asian development projects ramp up output.Information technology solutions provider Computacenter said profitability in the first half of its financial year will be comfortably ahead of the same period last year, and trading at this stage remains in line with management expectations for the year as a whole.--jh