Shares in food and sweeteners manufacturer Tate & Lyle were falling heavily on Friday after the stock's rating was cut by Credit Suisse from 'outperform' to 'neutral'. The bank said its greatest concern is a proposal in Mexico to tax soft drinks which would reduce demand the group's high-fructose corn syrup. It has cut its earnings per share estimates for Tate & Lyle by 7-8% and lowered its price target from 930p to 800p.Falling metal prices were weighing on mining stocks today, with Fresnillo, Randgold, Vedanta, Antofagasta, Anglo American and ENRC falling sharply as gold, silver and copper values took a hit. Banking stocks were also out of favour with domestic lenders RBS, Lloyds and Barclays among the worst performers. RBS, which announced this morning the sale of a further 20% stake in Direct Line Insurance, was being weighed down by comments by Investec which said that the third-quarter trading statement on November 1st "may (once again) prove to be a poor time to own the shares!"Meanwhile, Citigroup has upgraded its rating for supermarket chain Sainsbury from 'sell' to 'neutral', saying it expects a "big improvement" in sales trends in the second quarter. "On both sales and earnings we anticipate that Sainsbury's 1H will show substantially more progress than either of its UK rivals. This is not a 'sell' in our opinion," said analysts Alastair Johnston and Pradeep Pratti.GKN was on the up after Investec raised its target price on the stock from 395p to 410p, maintaining a 'buy' rating. BP's shares rallied as investors speculated on rumours of a takeover bid by US energy giant Exxon Mobil. The oil and gas company has been surrounded by market chatter of a takeover since its share price was hit by the Gulf of Mexico disaster in 2010.FTSE 100 - RisersShire Plc (SHP) 2,594.00p +2.05%Sainsbury (J) (SBRY) 398.70p +1.97%GKN (GKN) 361.70p +1.69%Pearson (PSON) 1,301.00p +1.17%Reed Elsevier (REL) 845.00p +1.14%BP (BP.) 444.75p +1.06%Centrica (CNA) 401.80p +1.06%William Hill (WMH) 423.40p +1.00%Persimmon (PSN) 1,122.00p +0.99%Land Securities Group (LAND) 934.00p +0.92%FTSE 100 - FallersTate & Lyle (TATE) 753.50p -3.89%Vedanta Resources (VED) 1,125.00p -3.60%Antofagasta (ANTO) 855.50p -3.44%Randgold Resources Ltd. (RRS) 4,701.00p -2.89%Fresnillo (FRES) 1,039.00p -2.81%Anglo American (AAL) 1,592.00p -2.63%Barclays (BARC) 273.65p -1.67%Prudential (PRU) 1,182.00p -1.66%Standard Chartered (STAN) 1,539.00p -1.60%Lloyds Banking Group (LLOY) 75.44p -1.51%NR