The miners were the worst performers on Wednesday afternoon, with blue chips Antofagasta, Rio Tinto and BHP Billiton dragging the sector down.Rio Tinto reported that some customers have asked for deliveries of metals to be delayed, signalling that global economic weakness is hitting demand for commodities. "It is noticeable that markets are somewhat weaker," Rio Tinto chief executive Tom Albanese is quoted as saying in the Financial Times. AIM-listed Vatukoula Gold Mines fell after seeing a slight dip in production at its 100%-owned gold mine in Fiji in the three months to the end of August. Meanwhile, the fixed line telecommunications sector was among the best performing sectors, with FTSE 250 phone and broadband provider TalkTalk giving the category a lift, after a kind word from Evolution Securities."Self-help and the opportunity afforded by expanding its network to cover 93% of the country should help stabilise revenues and propel the company towards its 20% margin target. Add in significant strategic value in ownership of over 20% of the UK broadband market and a very low valuation, we think more than enough scepticism is baked into the current share price," said analyst Steve Malcolm.While the broker cuts its target price from 185p to 180p - to reflect the first quarter trading statement, recent line rental increases and exceptional restructuring charges - it said that it still sees "significant value in the shares".Sector peer BT is also in demand.BCTop performing sectors so far todayIndustrial Transportation 2,210.10 +1.87%Personal Goods 24,067.30 +1.41%Fixed Line Telecommunications 2,119.71 +0.94%Banks 3,468.27 +0.48%Electronic & Electrical Equipment 2,607.19 +0.47%Bottom performing sectors so far todayMining 20,728.81 -1.87%Food & Drug Retailers 4,290.78 -1.40%Beverages 9,499.00 -1.32%Forestry & Paper 5,649.58 -1.22%Oil & Gas Producers 7,733.86 -1.17%