(ShareCast News) - The FTSE 100 index was scuttling crabwise on Wednesday, as markets held their powder dry as Britain appointed a new Prime Minister later in the day and a day ahead of the Bank of England expected policy tinkering. Commodities heavyweights Antofagasta, Glencore, BHP Billiton and Fresnillo dominated the upper echelons thanks in part to rebounding metals prices and adjustments of risk appetite.As a major market for natural resources, China's economic data is always closely monitored by sector watchers. The trade surplus for the People's Republic narrowed to $48.11bn in June from $49.98bn a month earlier as exports fell.Exports dropped 4.8% in June compared to a year ago following a 4.1% drop in May, according to the General Administration of Customs. Economists had expected a 5% decline. Imports decreased 8.4% year-on-year in June, more than the 6.2% slide expected by analysts, following a 0.4% fall in May."The inability to boost exports is likely to increase the pressure on the yuan in the short term, which in turn could well see it decline further towards 6.80 against the US dollar," said Michael Hewson, chief market analyst at CMC Markets.Burberry was strutting its stuff, with the shares sashaying more than 6% higher as its first-quarter sales were not as bad as feared. Like-for-like retail sales dropped 3% in the first quarter, beating the consensus 5% fall that had been forecast by analysts."In what remained a challenging external environment, underlying retail sales were flat in the first quarter," chief executive Christopher Bailey said, pointing to retail revenue being unchanged at the underlying level at £423m, indeed rising 4% at reported exchange rates. "In this context, we continue to focus on managing our business with agility whilst implementing the ambitious evolution of our strategies and ways of working we outlined in May, to position Burberry for long-term growth. These plans are now well underway and on track to deliver our financial goals."Rolls-Royce was another riser as news emerged from the Farnborough Airshow. Chief executive Warren East said the engine maker could boost its profitability by £1bn if tough targets, in addition to cost cuts already identified by the company, can be hit. East told reporters he was "pleased" with the progress being made on his transformation plan for the engineering company, adding that it was on track to take between £150m and £200m of costs out of the business by 2017.Goldman Sachs said their conversation with management had provided reassurance that the company has not yet seen the recent slowdown in widebody orders automatically translating into a need to trim production plans, though it could be needed if orders do not improve in the next 18-24 months. "Overall there is a path to improved cash flow, providing the XWB remains on track, however nearer term headwinds create heightened uncertainty. Improved engine parkings in H2 could alleviate some of this pressure."House builders were among the fallers as Barratt Developments admitted the Brexit vote could slow the rate of building. The group revealed full year profit before tax was to increase by around 20% to £680m, in line with market expectations, but told reporters it could reduce the rate at which it builds houses due to a possible slowdown from Brexit. Total completions, including joint ventures, increased by 5.3% to 17,319, as a result of strong consumer demand during the financial year, the trading statement revealed.But chief executive David Thomas told Reuters that contingency plans in place have resulted in management taking "appropriate measures to reduce our risk, such as reassessing land approvals, as we continue to monitor the market." Thomas added that Barratt would be looking at "the extent to which we should slow down our build programmes", as well as whether or not to bid for land coming on to the market. Market MoversFTSE 100 (UKX) 6,686.88 0.09%FTSE 250 (MCX) 16,823.47 0.10%techMARK (TASX) 3,299.21 0.05%FTSE 100 - RisersAntofagasta (ANTO) 526.50p 8.33%Burberry Group (BRBY) 1,278.00p 6.23%Glencore (GLEN) 193.35p 3.95%BHP Billiton (BLT) 1,032.50p 2.89%Rolls-Royce Holdings (RR.) 743.00p 2.62%CRH (CRH) 2,229.00p 2.01%Fresnillo (FRES) 1,965.00p 1.87%St James's Place (STJ) 839.50p 1.70%Kingfisher (KGF) 328.80p 1.64%Aviva (AV.) 387.90p 1.60%FTSE 100 - FallersGKN (GKN) 276.70p -2.57%Berkeley Group Holdings (The) (BKG) 2,623.00p -2.56%ITV (ITV) 187.00p -1.94%Diageo (DGE) 2,093.00p -1.92%Schroders (SDR) 2,535.00p -1.55%Barratt Developments (BDEV) 407.70p -1.35%BT Group (BT.A) 401.30p -1.35%TUI AG Reg Shs (DI) (TUI) 987.00p -1.30%London Stock Exchange Group (LSE) 2,607.00p -1.25%Barclays (BARC) 146.95p -1.08%