London open: Risk appetite sinks ahead of key economic data

The FTSE 100 dropped sharply in early trading on Wednesday as economic data from China continues to disappoint, while nerves were setting in ahead of some key risk events later on in the week.Activity in China's services sector remained sluggish in June with the official non-manufacturing purchasing managers' index falling from 54.3 to a nine-month low of 53.9 in June.Meanwhile, separate data published by HSBC/Markit showed that the services PMI edged up to 51.3 from May's reading of 51.2. However, the rate of expansion in new orders was the weakest in 55 months.HSBC's Chief Economist for China Hongbin Qu said that "the underlying growth momentum is likely to be softening for services sectors, along with the slowdown of manufacturing growth [...] we expect slower growth in service sectors in the coming months". A barrage of economic data elsewhere is due out later on today, including services PMIs from the UK, Europe and US, Eurozone retail sales and ADP employment figures. Jobless claims in the States are also being released today, one day early due to the Independence Day holiday tomorrow.Meanwhile, markets are also looking ahead to the European Central Bank and Bank of England (BoE) which are to reveal their latest policy decisions on Thursday afternoon with all eyes turning to Mark Carney as he heads up his first meeting as BoE Governor.However, the big event of the week is likely to be the US non-farm payroll report due out on Friday with investors waiting nervously given that a positive surprise could prompt the Federal Reserve to move more quickly to scale back its stimulus programme.FTSE 100: Miners, ex-divs and financials fallConcerns over a slowdown in China were weighing heavily on mining stocks early on with BHP Billiton, Anglo American and Glencore Xstrata among the worst performers. Burberry was trading firmly in the red after going ex-dividend, along with heavyweights British Land and Babcock.Banking group Barclays was also lower after S&P cut its long-term counterparty credit rating for the company by one notch from 'A+' to 'A'. The agency said that the banks' debt holders "face heightened credit risk owing to the industry's tighter regulation, fragile global markets, stagnant European economies and rising litigation risk stemming from the financial crisis".Heading the other way was Tullow Oil, rising strongly after the company said that first-half revenue totalled $1.3bn, slightly ahead of the $1.2bn reported the year before. The company delivered a 60% success ratio over the nine exploration and 11 appraisal wells drilled during the first six months of the year.Sector peer Shell however fell despite revealing upbeat drilling results from an exploratory well in the Gulf of Mexico. The well, located 75 miles offshore in the De Soto Cayon Block 393 in 7,446 feet (ft) of water, encountered more than 500ft of net oil pay after being drilled to a total depth of 26,385ft.FTSE 250:Spirent Communications shares tumbled after the technology testing company revealed weaker-than-expected revenues for the second quarter. Group revenue is expected to fall by $26m to $92.7m for the three months to the end of June after weak orders in the first quarter, Spirent said in a trading statement. Pizza delivery firm Domino's Pizza was also down despite reporting 11.7% sales growth in the second quarter. The company said that the results come on top of "very strong comparatives" from last year.Halfords, HomeServe and TalkTalk were lower after going ex-dividend.FTSE 100 - RisersTullow Oil (TLW) 1,060.00p +2.61%ARM Holdings (ARM) 817.50p +1.24%London Stock Exchange Group (LSE) 1,402.00p +0.43%British Sky Broadcasting Group (BSY) 814.50p +0.18%Next (NXT) 4,640.00p +0.15%FTSE 100 - FallersAnglo American (AAL) 1,225.00p -4.30%CRH (CRH) 1,304.00p -3.69%Glencore Xstrata (GLEN) 265.95p -3.64%Fresnillo (FRES) 885.50p -3.59%BHP Billiton (BLT) 1,652.50p -3.42%Barclays (BARC) 273.80p -3.25%International Consolidated Airlines Group SA (CDI) (IAG) 259.00p -3.11%Vedanta Resources (VED) 1,007.00p -3.08%Rio Tinto (RIO) 2,618.00p -2.80%Old Mutual (OML) 179.30p -2.71%FTSE 250 - RisersCOLT Group SA (COLT) 102.40p +1.39%Fisher (James) & Sons (FSJ) 990.50p +1.07%Dialight (DIA) 1,112.00p +0.91%Aveva Group (AVV) 2,268.00p +0.76%Countrywide (CWD) 534.00p +0.75%Petra Diamonds Ltd.(DI) (PDL) 113.30p +0.71%Devro (DVO) 291.70p +0.62%Centamin (DI) (CEY) 30.98p +0.49%Anite (AIE) 133.60p +0.45%DCC (DCC) 2,572.00p +0.39%FTSE 250 - FallersDomino's Pizza Group (DOM) 625.50p -6.50%Perform Group (PER) 475.00p -5.94%Polymetal International (POLY) 465.40p -5.83%Hochschild Mining (HOC) 157.00p -4.85%Spirent Communications (SPT) 128.00p -4.76%Ferrexpo (FXPO) 134.10p -4.01%Homeserve (HSV) 274.50p -3.89%Man Group (EMG) 82.30p -3.40%Lonmin (LMI) 253.80p -3.31%TalkTalk Telecom Group (TALK) 221.50p -3.11%