- Aberdeen drops as AuM fall three per cent- Retailers mixed as companies report festive sales- Mining stocks broadly higher, BHP Billiton upgradedtechMARK 2,841.00 +0.01%FTSE 100 6,821.68 +0.03%FTSE 250 16,275.67 -0.11%Mixed corporate results weighed on UK markets on Thursday morning, as the FTSE 100 opened more or less flat after hitting an eight-month high the previous session.Aberdeen Asset Management was providing a drag in London early on after a subdued first-quarter performance, while a number of updates from the retail sector disappointed as companies revealed their sales from the key festive season. Heavyweight mining stocks, however, were limiting downside on the resource-heavy FTSE 100 this morning.London's benchmark index, which rose to 6,819.86 on Wednesday - its highest level since May 22nd 2013 - was little changed in early trade.Investors were also showing caution after Frankfurt's DAX and New York's S&P 500 indices reached record highs yesterday.Aberdeen drops, retailers mixedAberdeen Asset Management fell sharply after reporting a 3% drop in assets under management during its first quarter. The fund manager also warned that further volatility in markets and investor sentiment "is likely in the coming months".Associated British Foods, the food ingredients company and owner of Primark, was also lower after delivering a mixed performance in its first quarter with a strong retail performance offset by a sharp drop in Sugar revenues.Electrical retailer Dixons was a heavy faller this morning after underwhelming investors with 3% like-for-like (LFL) sales growth in its third quarter. The company warned that it is facing "some very strong comparable in the fourth quarter", saying that the remainder of the financial year will be "more modest than the year to date".Home-shopping group N Brown said that LFL sales growth slowed from 7.8% in the first half to 5.1% in the third quarter due to an unusually mild autumn.In contrast, Halfords gained after beating third-quarter forecasts with a 5.2% jump in group LFL sales, helped by strong growth from cycling products.Argos and Homebase owner Home Retail also rose after saying that full-year profits will come in at the top-end of market forecasts following decent LFL sales growth in its third quarter.Mining stocks were broadly higher this morning with BHP Billiton among the best performers after Citigroup upgraded the stock to 'buy'. Fresnillo, Antofagasta, Anglo American and Glencore Xstrata were also higher.United Utilities was lifted by an upgrade by Morgan Stanley to 'overweight'; Royal Mail was pushed lower by a downgrade from Beaufort Securities to 'hold'; Intertek fell after Berenberg cut the stock to 'hold'.FTSE 100 - RisersUnited Utilities Group (UU.) 687.50p +4.32%Fresnillo (FRES) 719.50p +3.38%BHP Billiton (BLT) 1,843.00p +2.87%Antofagasta (ANTO) 807.00p +2.15%Anglo American (AAL) 1,360.00p +2.06%Severn Trent (SVT) 1,672.00p +1.89%Glencore Xstrata (GLEN) 324.75p +1.66%Rio Tinto (RIO) 3,303.00p +1.51%Centrica (CNA) 318.90p +1.08%Tullow Oil (TLW) 872.00p +1.04%FTSE 100 - FallersAberdeen Asset Management (ADN) 430.00p -4.17%Associated British Foods (ABF) 2,632.00p -2.37%Intertek Group (ITRK) 2,915.00p -2.15%Royal Mail (RMG) 606.00p -1.46%Pearson (PSON) 1,292.00p -1.45%Lloyds Banking Group (LLOY) 85.09p -1.40%Royal Bank of Scotland Group (RBS) 370.70p -1.15%British Sky Broadcasting Group (BSY) 860.00p -1.09%GKN (GKN) 399.40p -1.04%Old Mutual (OML) 193.80p -0.97%FTSE 250 - RisersHalfords Group (HFD) 490.00p +6.29%Polymetal International (POLY) 532.00p +3.50%Home Retail Group (HOME) 207.00p +2.99%CSR (CSR) 699.00p +2.79%Millennium & Copthorne Hotels (MLC) 597.50p +1.79%Ladbrokes (LAD) 175.80p +1.62%Imagination Technologies Group (IMG) 194.40p +1.46%Stagecoach Group (SGC) 379.50p +1.42%Pennon Group (PNN) 686.00p +1.33%WH Smith (SMWH) 1,034.00p +1.17%FTSE 250 - FallersSVG Capital (SVI) 426.10p -8.56%Xaar (XAR) 1,016.00p -5.40%Premier Oil (PMO) 292.70p -4.97%Brown (N.) Group (BWNG) 541.00p -3.31%Ocado Group (OCDO) 508.00p -2.50%Dixons Retail (DXNS) 49.14p -2.50%KCOM Group (KCOM) 101.50p -2.22%Bank of Georgia Holdings (BGEO) 2,434.00p -1.85%NMC Health (NMC) 450.10p -1.72%Daejan Holdings (DJAN) 4,618.00p -1.54%BC