UK stocks are set for a sharp fall on Tuesday morning, according to city sources, tracking Asian indices lower as a warning from Standard & Poor's rattled sentiment overnight.The ratings agency said that several Eurozone countries have been put on credit watch negative as a result of deepening economic and political turmoil in the single currency bloc. If EU leaders do not reach an agreement to resolve the crisis, the ratings of 15 countries - including powerhouses Germany and France - could be at risk."Systemic stresses in the Eurozone have risen in recent weeks to the extent that they now put downward pressure on the credit standing of the euro zone as a whole," S&P said in a statement.The FTSE 100 is expected to open down 55 points from yesterday's close of 5,568. IN COMPANY NEWS THIS MORNING...Anglo American's board has approved the Grosvenor project, a 5m tonne per annum metallurgical coal operation in the Bowen Basin of Queensland, Australia. Capital expenditure for the project is expected to be $1.7bn on a nominal basis "representing a highly competitive capital intensity ratio." Chief executive Cynthia Carroll said, "Grosvenor is the first of our next phase growth projects and will initiate our industry leading production growth of metallurgical coal from our Australian business over the next decade."Heating and plumbing giant Wolseley has seen revenues grow 5% in the first quarter from £3,471m to £3,641m, as strong growth in the USA offset lower growth in some of its European businesses. Trading profit was 16% ahead of last year at £185m, while the gross margin improved by 0.1% to 27.1%.Mining giant Xstrata has increased its total mineral resource estimate at the Las Bambas and Corroccohuayco projects in southern Peru and at El Pachón in Argentina. "Our significant and expanding mineral resource base in South America has laid the foundations for our approved organic growth programme that will increase copper production by more than 50% to 1.5 million tonnes of copper per year by the end of 2014 and offers great potential for further substantial copper production growth in the region," said chief executive Charlie Sartain.BC