Sector movers: London market retreats as mining, oil stocks plummet

London market slipped back from last week's high as it commenced trading on Tuesday, following a bank holiday weekend, with Greece weighing heavily on investor sentiment.At 16:17 BST, the FTSE 100 was back below the 7,000 mark at 6950.20, down 1.16% or 81.52 points, as natural resources stocks, chiefly mining, minerals and oil companies took a hammering owing to various factors.Mining stocks tumbled as a stronger dollar, uncertain Chinese demand and a reiteration of its bearish stance on commodities, especially copper, by Goldman Sachs dented trading. Additionally, gold prices also took a hit following with the end of Indian seasonal buying and a stronger dollar hitting investor sentiment.Traders in Mumbai reported that Indian gold imports had fallen from an average of 67 tonnes in the week ended 21 April, to an average of six tonnes for the week ended 22 May. It prompted gold to shed as much as $15 or 1.31% in intraday trading in Europe.Miners invariably bore the brunt, with Fresnillo (down 3.8%), Randgold Resources (down 3.31%) and Anglo American (down 2.92%) among the top FTSE 100 fallers. The wider market also saw Evraz (down 4.67%) and Acacia Mining (down 4.07%) witness a sell-off.A downbeat day also saw Rio Tinto (down 1.07%), Glencore (down 1.16%), Lonmin (2.23%), Antofagasta (2.52%), BHP Billiton (down 2.59%), Anglo American (down 2.82%) and Vedanta Resources (2.85%) register losses.Meanwhile, oil and gas stocks were in retreat as oversupply concerns returned to dent industry confidence, while JPMorgan downgraded Soco International (down 0.65%) and Tullow Oil (down 4.17%). Premier Oil (down 3.82%) also among those to take a hit while the blue chips BP (down 1.32%) and Shell ('A' shares down 2.00% / 'B' shares down 2.32%). However, Weir Group (up 3.36%) bucked wider trends with Jefferies giving it a thumbs up.It added that Weir continues to be a stock that is gathering interest with investors, and with last week's US rig count data showing a slowing pace of decline, the broker suspects this will increase further.Top five losers:Industrial Metals & Mining 1,707.77 -83.71 -4.67% Gas, Water & Multiutilities 6,106.21 -108.12 -1.74%Oil & Gas Producers 7,148.08 -123.67 -1.70% Pharmaceuticals & Biotechnology 13,297.93 -224.97 -1.66% Mining 14,021.91 -229.23 -1.61%