London's leading share index closed pretty much where it started the day yesterday, staging an impressive recovery even as Standard & Poors' downgrade of Italy cast a shadow.In a fresh blow to the debt-stricken country, the ratings agency downgraded its rating on Italian sovereign debt by one notch on Monday night, citing poor economic growth and a "fragile governing coalition". While still considered investment grade debt, the rating was cut from A+ to A, five levels above junk. S&P has maintained its outlook as negative, a stance it has taken since May.Carnival was one of the top performers, steaming ahead after the cruise operator reported its third quarter earnings on Tuesday afternoon, showing that it was able to offset higher-than-expected fuel prices in the period to keep net income stable. For the three months ended 31 August, net income totalled $1.34bn, up from $1.30bn, despite fuel prices jumping 45% to $686 per metric ton, from $473 in the third quarter of 2010. In June, the group's guidance was for prices to be $670 per metric ton. Mining colossus Rio Tinto was in demand after increasing its copper mineral resources at its wholly-owned Kennecott Utah Copper Bingham Canyon Mine in the USA.Iconic British luxury brand Burberry was among the high risers in the opening minutes, making gains a day after its catwalk show at London Fashion Week.Department store group Debenhams rose after saying it expects full-year profits to surpass consensus estimates, after a strong end to the year.Bio-degradable plastics firm Symphony Environmental plummeted as gross profits fell from £2.3m to £2.18m.Mobile gaming firm Probability was in demand after bookmaker William Hill said that any offer it would make for the company would be in cash.Russia-focused oil and gas firm PetroNeft Resources fell despite announcing a maiden profit in the first half of 2011.Manoj Ladwa, senior trader at ETX Capital, said markets were acting fairly robustly across most asset classes despite the increasingly negative news flow, suggesting traders "are yet to switch into full risk-off mode". "Within the first hour of trading, equities have moved into the black having started off the day in negative territory, as investors opt for stocks with more defensive qualities - but any rally could be short-lived as the market waits in anticipation for the Federal Reserve to show its hand," he said."While the market is not expecting another round of quantitative easing, if the Fed fails to implement measures to further stimulate the US economy, asset prices could retreat fairly sharply," Ladwa said.Drug developer Oxford Pharmascience was out of favour after losses widened in the first half of 2011.Specialist Energy is showing signs of promise after unveiling first half results that saw it move into the black at the operating level. The company saw its revenue fall from £18.5m to £14.3m, but after a £3m saving on costs the operating profit moved into the black to £0.5m (2010 H1: -2.1m). FTSE 100 - RisersHargreaves Lansdown (HL.) 480.20p +8.50%Carnival (CCL) 2,145.00p +6.56%ITV (ITV) 59.30p +4.68%Fresnillo (FRES) 1,943.00p +4.07%ARM Holdings (ARM) 619.00p +3.77%Cairn Energy (CNE) 296.50p +3.64%Burberry Group (BRBY) 1,500.00p +3.45%Glencore International (GLEN) 451.55p +3.33%IMI (IMI) 799.00p +3.30%Whitbread (WTB) 1,661.00p +3.23%FTSE 100 - FallersInternational Consolidated Airlines Group SA (IAG) 150.20p -2.59%Vedanta Resources (VED) 1,305.00p -1.73%Investec (INVP) 397.50p -0.40%Resolution Ltd. (RSL) 245.50p -0.20%Amec (AMEC) 909.00p -0.11%Autonomy Corporation (AU.) 2,531.00p 0.00%3i Group (III) 198.40p +0.05%Sainsbury (J) (SBRY) 281.00p +0.14%Aggreko (AGK) 1,787.00p +0.22%Tullow Oil (TLW) 1,367.00p +0.22%FTSE 250 - RisersEuromoney Institutional Investor (ERM) 602.50p +8.07%Regus (RGU) 78.45p +6.23%Barratt Developments (BDEV) 82.20p +5.72%Ashmore Group (ASHM) 410.00p +5.53%Persimmon (PSN) 462.00p +4.95%Genus (GNS) 1,042.00p +4.72%SEGRO (SGRO) 238.60p +3.87%Aegis Group (AGS) 130.30p +3.82%Aveva Group (AVV) 1,558.00p +3.80%Spirit Pub Company (SPRT) 41.25p +3.77%FTSE 250 - FallersInternational Personal Finance (IPF) 211.10p -5.29%Renishaw (RSW) 1,106.00p -3.57%Carpetright (CPR) 486.10p -3.17%COLT Group SA (COLT) 104.40p -2.97%Daily Mail and General Trust (DMGT) 367.20p -2.86%Tullett Prebon (TLPR) 369.40p -2.71%Ocado Group (OCDO) 115.70p -2.28%Exillon Energy (EXI) 288.30p -2.27%JD Sports Fashion (JD.) 840.50p -2.21%Perform Group (PER) 215.00p -2.18%