Markets are expected to open slightly lower on Friday morning with the FTSE 100 pulling back after a seven-week high ahead of the meeting of G20 leaders. City sources predict the FTSE 100 will open down 18 points from yesterday's close of 6,634. The last time the index finished higher was on May 30th when it closed at 6,657.The G20 is expected to discuss many issues at its meeting in Moscow, including high unemployment, market volatility and the global economic recovery. Meanwhile, according to Senior Market Analyst Michael Hewson from CMC Markets, the consequences of recent central-bank stimulus chatter is likely to be high on the agenda "given the recent weakness in emerging-market currencies caused by Fed tapering talk, as well as the sharp rise in interest rates around the world".Hewson said: "This rise in global bond yields and capital outflow from EM currencies could well have been part of the reason why we saw the Fed Chairman [Ben Bernanke] soften his tone on tapering this week."Both the S&P 500 and Dow Jones closed at fresh all-time highs last night after economic data and a raft of corporate earnings came in better than expected.After the closing bell however, tech giants Google and Microsoft both missed Wall Street forecasts. The gloomy figures were tempered slightly by Moody's which upgraded the US's sovereign rating outlook from 'stable' to 'negative'.Stocks to watch Vodafone reported a drop in second-quarter revenue, blaming ongoing economic and regulatory pressures in its key market of Europe. Group service revenue including joint ventures dropped 3.5% year-on-year to £10.1bn in the three months to end of June.AstraZeneca has completed the acquisition of New Jersey-based specialty pharmaceutical company Omthera Pharmaceuticals. The purchased company is focused on the development andcommercialisation of new therapies for abnormal levels of lipids in the blood, referred to as dyslipidemia.Sirius Minerals has rejected a report that says the case for its flagship potash project has not been proved. The report was written by consultants AMEC for the North York Moors National Park Authority, which will decide whether to let the project go ahead.BC