After decent gains the day before, the FTSE 100 is expected to open slightly lower on Tuesday morning as markets turn cautious ahead of the Federal Open Market Committee meeting which concludes tomorrow.City sources predict the FTSE 100 will open down five points from yesterday's close of 6,330. Wall Street benchmarks trimmed gains by the close of trade last night after the Financial Times suggested that Fed Chairman Ben Bernanke is likely to signal tomorrow that the central bank is close to tapering its $85bn-a-month in asset purchases. "Investors remain sceptical about adding to positions before the meeting which could signal a potential slowdown to the Fed's bond buying programme," said Lee Mumford, Financial Sales Trader at Spreadex.Several key economic indicators are out in the UK this morning, including the consumer price index, the producer price index and real price index. Over in Germany, there'll be the latest release of the ZEW economic sentiment survey, while in the States, eyes will be on the US Aconsumer price index, building permits and housing starts.Stocks to watchTemporary power and temperature control supplier Aggreko has left its full-year guidance unchanged after an in-line performance in the first half, though trading in its two main divisions remains mixed. The company said that both underlying and reported revenues in the six months to June 30th will be up around 5.0% on last year, while trading profits will be flat. UK hotel and restaurant group Whitbread reported a 3.1% rise in total like-for-like sales (LFL) for the 13 weeks to May 30th. The results were driven by a 8.0% LFL growth in sales at its Costa coffee chain and a 2.7% rise in LFL sales at its Premier Inn family of hotels.Beverage giant SABMiller and Kopparberg Brewery AB have entered into a co-operation agreement for the long term licensing of Kopparberg cider products in selected markets. BC