London Stock Exchange is the best performer today after Abu Dhabi guaranteed the debt position of Dubai World, one of the flagship companies of its neighbour Dubai.Borse Dubai, which is state run, owns a 20.56% stake in the LSE, and there had been fears it would have to sell its stake to raise money if the situation in Dubai had deteriorated significantly.Coffee shop to hotel owner Whitbread is another riser after a bullish trading update. Broker Charles Stanly upped its 2010 profit forecast by 9.5% to £230m (EPS 90.0p), in line with the improved company guidance. Its 2011 forecast rises by 11.6% to £240m (EPS 94.0p), reflecting the higher base and stronger sales assumptions. Lloyds Banking is lower as the underwriters handle the small rump left after the £13.5bn rights issue. More than 95% of shareholders took up the offer.FTSE 100 - RisersLondon Stock Exchange Group (LSE) 765.00p +10.15%Whitbread (WTB) 1,384.00p +4.06%Standard Chartered (STAN) 1,570.50p +4.04%Lonmin (LMI) 1,833.00p +3.91%Xstrata (XTA) 1,087.00p +3.82%Eurasian Natural Resources (ENRC) 899.00p +2.92%BG Group (BG.) 1,097.50p +2.81%Tullow Oil (TLW) 1,284.00p +2.72%FTSE 100 - FallersHammerson (HMSO) 379.80p -1.30%Lloyds Banking Group (LLOY) 55.64p -1.03%Reckitt Benckiser Group (RB.) 3,248.00p -0.95%British Sky Broadcasting Group (BSY) 574.00p -0.69%RSA Insurance Group (RSA) 116.00p -0.60%Admiral Group (ADM) 1,101.00p -0.54%Johnson Matthey (JMAT) 1,493.00p -0.47%Centrica (CNA) 264.40p -0.45%