Markets opened with moderate losses on Wednesday morning as investors turned nervous ahead of the Bank of England's inflation report, the first under the governorship of Mark Carney. The heavyweight mining sector was again providing a drag on the FTSE 100 as metals prices fell, while a number of blue chips were heading lower after going ex-dividend, pushing London's benchmark index into the red for the fourth straight day.Carney, who took over from Mervyn King in early July, is expected to unveil forward guidance later this morning in an attempt to convince consumers, small businesses and international money markets that only when the upturn is established will borrowing costs rise.The move is thought to encourage borrowing and less saving amongst businesses and consumers, thus giving a boost to the economy."It is widely anticipated that new governor Mark Carney will look to pledge to keep interest rates low for a set period of time, in a form of monetary forward guidance, and he could even set a monetary threshold, like the unemployment rate as a benchmark, or a growth target, for when we can expect them to go higher again," said Senior Market Analyst Michael Hewson from CMC Markets."The problem is that given the recent improvement in economic data, questions are now being raised as to whether we need forward guidance at all, as it could be counterproductive." Sentiment has also been dampened by losses on Wall Street overnight, as a worries about the Federal Reserve tapering asset purchases sent US stocks lower following comments from a number of officials that a phased withdrawal could be just around the corner.FTSE 100: Miners extend losses, Randgold disappointsAfter some heavy falls on Tuesday, miners were once again in negative territory as metals prices continued to weaken. Randgold firmly lower after a 17% drop in the average gold price during the second quarter reduced profit by 34% from the first three months of the year. Sector peers Fresnillo, Glencore Xstrata, Rio Tinto, Antofagasta and BHP Billiton were also lower.A number of heavyweight stocks were also weighing on the Footsie today after going ex-dividend, meaning that from today new investors won't be able to get their hands on the firms' latest payouts. Ex-div stocks today include Barclays, BG Group, BT Group, GlaxoSmithKline, Reckitt Benckiser, Reed Elsevier and Unilever.Investors gave a cool reaction to third-quarter figures from TUI Travel despite the tour operator reiterating full-year guidance after an 18% jump in underlying operating profits.Savings, investment and insurance giant Old Mutual was heading the other way after half-year profits increased due to a rise in funds under management and client cash flows.Defensive stocks were also making small gains this morning, benefitting from a reduction in risk appetite, with pharmaceuticals Shire and AstraZeneca in demand, along with utilities firms Centrica and SSE.FTSE 250: United Drug slumps despite upbeat outlookUnited Drug, the provider of services to healthcare manufacturers and pharmacies, was trading firmly lower this morning despite saying that trading in the third quarter has been "strong". The company reiterated its guidance for 5-8% growth in adjusted diluted earnings per share this year.A number of stocks on the FTSE 250 also went ex-dividend today, including Dialight, Domino's Pizza, Greene King, Hiscox, Jupiter, Pennon, RPC, Synergy Health, Spirent Communications and St Modwen Properties.FTSE 100 - RisersOld Mutual (OML) 202.70p +5.30%Standard Chartered (STAN) 1,581.50p +0.89%Centrica (CNA) 393.50p +0.51%Shire Plc (SHP) 2,403.00p +0.46%SSE (SSE) 1,583.00p +0.38%Kingfisher (KGF) 398.90p +0.25%AstraZeneca (AZN) 3,277.00p +0.15%Vedanta Resources (VED) 1,171.00p +0.09%Prudential (PRU) 1,194.00p +0.08%Royal Bank of Scotland Group (RBS) 317.90p +0.06%FTSE 100 - FallersTUI Travel (TT.) 381.20p -5.06%Randgold Resources Ltd. (RRS) 4,297.00p -2.96%BT Group (BT.A) 332.20p -1.89%Rio Tinto (RIO) 2,948.00p -1.72%Reckitt Benckiser Group (RB.) 4,644.00p -1.61%Reed Elsevier (REL) 830.50p -1.60%Unilever (ULVR) 2,639.00p -1.46%ARM Holdings (ARM) 876.50p -1.13%Whitbread (WTB) 3,267.00p -1.09%BP (BP.) 449.90p -0.98%FTSE 250 - RisersFerrexpo (FXPO) 173.20p +6.00%Centamin (DI) (CEY) 36.01p +2.77%esure Group (ESUR) 251.00p +2.03%Millennium & Copthorne Hotels (MLC) 563.50p +1.62%Menzies(John) (MNZS) 764.00p +1.60%Grainger (GRI) 185.70p +1.59%Regus (RGU) 188.20p +1.13%Evraz (EVR) 94.00p +1.08%African Barrick Gold (ABG) 112.80p +1.08%COLT Group SA (COLT) 102.40p +0.99%FTSE 250 - FallersUnited Drug (UDG) 340.10p -4.97%Greene King (GNK) 864.50p -3.68%Pennon Group (PNN) 676.00p -3.15%Lancashire Holdings (LRE) 782.00p -2.92%RPC Group (RPC) 460.30p -2.27%Hansteen Holdings (HSTN) 94.50p -2.07%QinetiQ Group (QQ.) 182.10p -1.94%Balfour Beatty (BBY) 242.80p -1.90%Kazakhmys (KAZ) 242.30p -1.90%Domino's Pizza Group (DOM) 561.50p -1.75%BC