(ShareCast News) - London's top-flight index was down 2.2% to 6,059.90 at 1515 BST, extending earlier losses following a weaker-than-expected US nonfarm payrolls report.Hikma Pharmaceuticals nudged a little higher after Goldman Sachs upgraded the stock to 'buy' from 'neutral' and lifted its price target to 2,840p from 2,210p. "We see the acquisition of Roxane Labs as the realisation of large transformational M&A that we had expected to be a key catalyst." GS said the deal makes Hikma the sixth-largest player in the US generics market and offers potential to further improve its market position, with the acquired high-value pipeline playing a key role.On the downside, Anglo American slid after saying late on Thursday that its South African subsidiary, Anglo American Platinum, is in discussions with Sibanye Gold regarding the sale of its Rustenberg operations. It said the discussions, which may or may not lead to a transaction, are in line with what the company has publicly stated, that it continues to pursue both a sale and listing option.Oil giant BP was under the cosh after Bank of America Merrill Lynch downgraded it to 'underperform' from 'neutral' and slashed its price target to 330p from 420p. The bank said incorporating its reduced macro forecasts - which suggest Brent oil prices will not recover far above $60 a barrel until 2018 - into its BP estimates indicates the company will run persistent and sizeable free cash flow shortfalls for the foreseeable future.Engineering group GKN was also under pressure after Investec downgraded the stock to 'hold' from 'buy' and cut its price target to 300p from 370p. "We adopt a more cautious view on the outlook for Driveline and Powder Met's revenue and profit growth to reflect a potential slowdown in auto production in China and other emerging markets," it said.More general, heavily-weighted mining stocks suffered the brunt of the losses, with Glencore, Antofagasta, BHP Billiton, Rio Tinto and Fresnillo all in the red as metals prices declined across the board, with the exception of aluminium.RisersHikma Pharmaceuticals (HIK) 2,352.00p +0.38%International Consolidated Airlines Group SA (CDI) (IAG) 565.50p +0.18% FallersAnglo American (AAL) 673.20p -7.14%Glencore (GLEN) 122.95p -6.11%Antofagasta (ANTO) 565.00p -5.28%BP (BP.) 338.30p -4.93%BHP Billiton (BLT) 1,055.50p -4.91%Rio Tinto (RIO) 2,235.50p -4.51%Fresnillo (FRES) 596.50p -4.10%GKN (GKN) 270.30p -3.91%Randgold Resources Ltd. (RRS) 3,733.00p -3.84%Weir Group (WEIR) 1,279.00p -3.69%