Markets are expected to open slightly higher on Tuesday morning, extending gains after a strong performance the day before. City sources predict the FTSE 100 will open up 12 points from yesterday's close of 6,506.19. Stocks surged the day before as traders took advantage of low volumes - with Wall Street closed for Labour Day - to push the London index up 1.5%. Better-than-expected manufacturing data from the UK, Eurozone and China and delays to possible US military action against Syria helped push stocks higher yesterday.However with US markets re-opening today the mood in Europe is expected to be a touch less bullish with gains likely to be limited."With a number of key central bank meetings to come over the next couple of days, as well as a huge US jobs report on Friday, investors are understandably cautious as we head towards the end of the week," said Market Analyst Craig Erlam from Alpari.Investors will be particularly nervous about the employment report given that it comes less than two weeks before the Federal Reserve's next policy meeting at which analysts now widely expect the central bank to begin tapering its asset-purchase programme."While the Fed isn't going to draw a conclusion on the state of the economy on that one release, it is the most current data available and could therefore prove decisive, given that the Fed until this point has been split on which move to start tapering," Erlam said.Stocks to watchVodafone will be in focus today after late last night reaching an agreement to sell its 45% stake in US outfit Verizon Wireless to Verizon Communications in a transaction valued at $130bn (£84bn) in cash and shares. Shareholders are expected to receive 71% of the net proceeds of the disposal.Pub group Greene King said that decent weather this summer and growing consumer confidence helped drive sales in its first quarter, with like-for-like (LFL) growth accelerating strongly. LFL sales in its largest business, Retail, were up 4.6% during the 18 weeks to September 1st, as the difficult comparatives of the Queen's Jubilee and the European football in 2012 were outweighed by the good weather. This was a pick-up from the meagre 0.6% LFL growth registered in Retail in the second half of the previous financial year.Spirent Communications said its Chief Executive Officer Bill Burns will step down from the company with immediate effect. Chief Financial Officer Eric Hutchinson will replace Burns in the interim while the technology firm searches for a successor.DS Smith, a company which supplies recycled packaging for consumer goods, has reported a positive start to the year, driven by a good performance across the group. Since the start of May, the group continued its strong delivery of synergies from the acquisition of SCA Packaging, and said the return on sales and return on average capital employed continued to improve as anticipated.