London shares are largely positive in early trade on Wednesday after yesterday's sell-off, with Europe's major stock markets rallying despite heavy falls on Wall Street and in Asia overnight. The blue-chip FTSE 100 index rises around 50 points, or 0.85%, to 5,985, but failing thus far to break back over the 6,000 mark, but mid and smaller companies make more modest gains, the FTSE 250 up just 0.2% at 16,563 and the small cap index nudging 0.3% to 4,513.

On the corporate front, engineering conglomerate Smiths (SMIN) heads the Footsie leader board, up close on 4% at £10.69, thanks to a 3% rise in pre-tax profit to £325 million, driven by improved margins in its Detection business and lower exceptional operating costs. Group revenue is down 2% to £2.9 million due to tougher trading at Smiths Interconnect and its oil services business John Crane. Andrew Reynolds Smith, the former boss of GKN Automotive, takes over from Philip Bowman as chief executive on 25 September.

Water supplier United Utilities (UU.) warns that revenue in the six months to 30 September is likely to remain flat and profit is expected to drop thanks to one-off costs relating to the recent water quality scare. But investors bat that news off, bidding the stock up 1.2% to 887p with limited impact anticipated on the all-important payout. Read Shares in-depth feature on the water sector in tomorrow's magazine.

Diesel engine specialist Johnson Matthey (JMAT) falls 2.7% to £22.55 as investors fret over a negative spill-over from the Volkswagen (VOW:FRA) diesel testing scandal in the US.

Among the bigger movers, travel firm On the Beach Group (OTB), trading at 207p, confirms the successful pricing of its placing of 52.17 million shares at 184p each. The company is an online retailer of affordable short-haul beach holidays. Read Shares exclusive web story.

Chinese electric scooter manufacturer Vmoto (VMT:AIM) tumbles 15% to 14p on its return to trading on AIM with news it is exiting battery controller business Nanjing Haiyong because it didn't generated the expected returns. FinnCap has reduced its full-year pre-tax profit forecast from AUD6 million to AUD5 million and lowered its target price from 35p to 27p.

Caza Oil & Gas (CAZA:AIM), down 13% to 1.63p, has issued 12.4 million shares to YA Global Master and Global Market Neutral Strategies at 1.3624p a share in relation to a $4 million convertible unsecured loan.

Property services minnow Styles & Wood (STY:AUIM) slumps 13% to 235p despite narrowing its half-year pre-tax loss on improved revenue and reporting an improving second half order book.

Digital publishing firm Publishing Technology (PTO:AIM) crashes 18% to 121p as the market reacts to a profit warning issued after close late yesterday. The CEO has also paid the price, exiting the struggling business. Shares flagged the ongoing struggles at the company as far back as October 2014, and again in May, but it seems that little real progress has been made in facing off its challenges.

Premier Oil (PMO) jumps 12% to 70.93p as a production update shows year-to-date output had averaged about 57.1 kboepd.

Server replication specialist WANdisco (WAND:AIM) talks up business progress and new customers, with Investec analysts calling it a 'turning point' for the company. Yet the market remains unconvinced about still huge losses on limited revenues, selling the shares down by nearly 10% to 146.5p.

Formation (FRM:AIM) leaps 20% to 9.13p on a trading update that says it has continued to perform exceptionally strongly. Full year pre-tax profit is seen at more than £1.75 million.

Elsewhere, Stanley Gibbons (SGI:AIM) rebounds 4.5% to 161p on a reassuring update, issued in response to a recent share price fall. The stamps, rare coins and antiques dealer concedes first half results may disappoint due to the timing of high value sales and weakness in China, though a bumper second half is expected and online sales are growing at a double-digit clip.

Alcoholic drinks giant Diageo (DGE) edges 3.5p higher to £17.20 after serving up a rather mixed AGM update. While CEO Ivan Menezes reminds the market weak emerging market currencies are crimping operating profits, he also flags a good start to the year with improving volume growth trends, notably in US spirits.

Diversified food business Real Good Food (RGD:AIM) sheds a penny to 51p on a mixed AGM trading statement. Entrepreneurial executive chairman Pieter Totte says overall sales are down in the opening weeks of the new financial year, caused by the impact of commodity price deflation on the Garretts Ingredients business.

Personal injury marketing firm NAHL (NAH:AIM) is up 3.2% to 346.9p as it posts a strong set of interim results with a 25.5% hike in the dividend to 6.25p a highlight.

GlaxoSmithKline (GSK) rises 1.3% to £12.63 due to a positive update on HIV drug Triumeq's progress in Phase IIIb clinical trials.

Real estate investor First Property (FPO:AIM) falls 4.8% to 36.6p on funds under management falling 17.1% to £271 million in the six months to 31 August after a fund management contract expired.

Issue Date: 23 Sep 2015