London midday: Stocks weighed down by economic data, oil and Greece

Disappointing economic data and a continued slide in the price of oil pushed UK stocks firmly into the red on Tuesday, with the FTSE 100 trading at its lowest in three weeks.Ongoing concerns about a Greek exit from the Eurozone were also doing their bit to dampen market sentiment further."The Greek situation hasn't gone away and it will hang over the market for the foreseeable future," said analyst David Madden from IG. "The election in Greece could be the beginning of the end of the eurozone and traders are scurrying to the safe-havens of gold and government bonds."London's FTSE 100 was trading down 0.5% at 6,387 by midday, though it had come off an intraday low of 6,328.59. The index has not closed below this level since 17 December.Figures showed that service-sector growth in the UK slowed more than expected last month with the purchasing managers' index (PMI) falling from 58.6 to 55.8. As such, the composite PMI declined from 57.6 to 55.2.Meanwhile, the final estimate of the Eurozone composite PMI for December was revised to 51.4, up on the month before but down from the original reading of 51.7.Oil was experiencing yet more selling pressure on Tuesday morning, with West Texas Intermediate (WTI) futures falling further below the $50-a-barrel (bbl) mark, a level not seen since April 2009.WTI was down 1.8% at $49.12/bbl by noon ahead of data from the Energy Information Administration this week, which is expected to show that US crude stockpiles increased last week, exacerbating a global supply glut which has hammered prices over the last few months.Investors were also showing caution ahead of a number of important economic indicators due out this week, including Eurozone inflation data, a Bank of England rate decision and the US non-farm payrolls report.Ashtead drops on United Rentals readacrossEquipment rental firm Ashtead dropped sharply early on, tracking declines seen in the share price of US peer United Rentals which was hit with a broker downgrade on Monday night.Evercore lowered its rating for United Rentals from 'buy' to 'sell', saying that the recent collapse in oil will affect energy investments and the construction market.Oil and gas stocks were under pressure again as oil prices dropped, with Nostrum Oil & Gas, Shell and Ophir Energy falling sharply.Mining stocks were edging higher, including Anglo American, Fresnillo, Rio Tinto and Randgold, after service-sector figures from China improved slightly. HSBC's China services PMI for December rose from 53 to 53.4.Defence, aerospace and energy manufacturing firm Senior rose after hiring Cobham's chief operating officer David Squires as its new chief executive officer, replacing Mark Rollins who is due to step down after 17 years with the group.Supermarket peers Tesco, Sainsbury's and Morrisons were all trading lower ahead of their Christmas trading updates due out over the next few days. Market MoverstechMARK 2,922.98 -0.65%FTSE 100 6,387.21 -0.47%FTSE 250 15,860.69 -0.38%FTSE 100 - RisersFresnillo (FRES) 793.50p +3.25%Randgold Resources Ltd. (RRS) 4,638.00p +2.25%Anglo American (AAL) 1,150.50p +2.13%TUI AG Reg Shs (Post- 16/12/14)(DI) (TUIJ) 1,069.00p +1.42%Rio Tinto (RIO) 2,913.50p +1.04%Old Mutual (OML) 185.80p +1.03%BG Group (BG.) 849.80p +0.96%SSE (SSE) 1,598.00p +0.88%Shire Plc (SHP) 4,524.00p +0.82%Standard Chartered (STAN) 954.50p +0.77%FTSE 100 - FallersAshtead Group (AHT) 1,106.00p -6.43%Travis Perkins (TPK) 1,765.00p -2.59%Hargreaves Lansdown (HL.) 960.00p -2.44%Sports Direct International (SPD) 696.50p -2.38%Kingfisher (KGF) 320.50p -2.32%ARM Holdings (ARM) 966.50p -2.08%Taylor Wimpey (TW.) 131.30p -1.87%Smiths Group (SMIN) 1,057.00p -1.86%InterContinental Hotels Group (IHG) 2,528.00p -1.86%Diageo (DGE) 1,788.00p -1.81%FTSE 250 - RisersMitchells & Butlers (MAB) 399.10p +5.50%Afren (AFR) 43.90p +3.25%Tate & Lyle (TATE) 616.50p +3.18%Lonmin (LMI) 170.80p +2.52%Drax Group (DRX) 432.10p +2.51%Saga (SAGA) 151.10p +2.30%Acacia Mining (ACA) 264.80p +2.20%Centamin (DI) (CEY) 61.90p +2.06%Evraz (EVR) 147.70p +1.86%Debenhams (DEB) 77.00p +1.85%FTSE 250 - FallersOcado Group (OCDO) 403.40p -3.95%SSP Group (SSPG) 278.90p -3.79%Ladbrokes (LAD) 104.70p -3.59%JD Sports Fashion (JD.) 489.00p -3.55%Ophir Energy (OPHR) 134.80p -3.44%Spire Healthcare Group (SPI) 355.10p -3.37%Just Retirement Group (JRG) 143.10p -3.18%Spectris (SXS) 2,016.00p -3.08%Premier Oil (PMO) 148.50p -3.00%Supergroup (SGP) 820.00p -2.84%