Miners are leading London's top stocks lower in early dealings on Thursday, while investors also have a stream of company updates to consider.Nine out of the ten worst performers are miners. Fresnillo, Xstrata, Antofagasta, Rio Tinto, Anglo American, Vedanta Resources, Eurasian Natural Resources, Kazakhmys and BHP Billiton are on offer.Supermarket chain Morrisons reported a 4.3% rise in like-for-like sales and left its expectations for the current year unchanged. Brewer SABMiller reported a 1% fall in lager volumes over the six months to September 30 as growth in Africa and Asia was offset by weakness in more developed markets. Oil company BG has had more good news in Brazil where well tests on the Iracema appraisal well in the Tupi area, Santos Basin, reported record productivity.Gas and electricity pipeline grid operator National Grid upped its interim dividend after posting a 16% rise in pre-tax profits. Pre-tax profit rose to £649m in the six month ended 30 September compared with £558m last time, supported by lower financing costs. The interim dividend has been increased from 12.6p to 13.6p.Anglo-Swiss drug giant AstraZeneca has submitted a New Drug Application (NDA) to the US Food and Drug Administration (FDA) for its Brilinta blood cot prevention treatment.Bike and car parts chain Halfords has upped the interim divided by a fifth after increasing first half profit by 24%, and remains confident that business over the next six months will beat the previous year. Water firm Pennon Group reported a 13% rise in half year pre-tax profit and said its businesses are 'well positioned in the current economic slowdown.'Building and civil engineering contractor Kier has announced the appointment of Paul Sheffield to succeed John Dodds as chief executive. Payment services group Paypoint reported a 10% drop in half year pre-tax profit but said it was confident about its growth prospects. Military decoy specialist Chemring reported a strong order book and said the outlook for 2010 remains in line with expectations.Profit fell at South African bank Investec during the first half, but was "comfortably" ahead of the second half of last year as assets under management rose almost 29%.Materials company Morgan Crucible said that demand for its products has stabilised after a soft summer and expects its performance over the second half of the year to be in line with expectations.Melrose said current trading is marginally ahead of management expectations for 2009 as the engineering conglomerate benefited from being exposed to different product sectors and geographical areas.FTSE 100 - RisersReckitt Benckiser Group (RB.) 3,160.00p +1.77%SABMiller (SAB) 1,686.00p +1.75%Cable & Wireless (CW.) 137.40p +1.10%BG Group (BG.) 1,150.00p +1.10%National Grid (NG.) 647.00p +1.09%Cairn Energy (CNE) 2,984.00p +1.05%Royal Bank of Scotland Group (RBS) 36.82p +0.97%Centrica (CNA) 258.50p +0.70%Schroders NV (SDRC) 1,015.00p +0.69%Severn Trent (SVT) 1,011.00p +0.60%FTSE 100 - FallersFresnillo (FRES) 896.00p -2.61%Xstrata (XTA) 1,106.00p -1.86%Antofagasta (ANTO) 925.00p -1.70%Rio Tinto (RIO) 3,255.50p -1.65%Anglo American (AAL) 2,594.00p -1.37%Vedanta Resources (VED) 2,420.00p -1.31%Eurasian Natural Resources (ENRC) 889.50p -1.28%Autonomy Corporation (AU.) 1,458.00p -1.22%Kazakhmys (KAZ) 1,313.00p -1.06%BHP Billiton (BLT) 1,859.00p -1.04%