The gloom has returned to FTSE 100 oil and gas giant BG (BG.) which has nudged down its production guidance for the second time in four months. The shares dipped 3% in early trading (5 Feb) to £10.67 after management said that 2013 production would be in the range of 630,000 to 680,000 barrels of oil equivalent (boe) per day.

Given that 2012's average daily production was 657,000 boe, the new guidance implies that output could be up to 4% less in 2013. The latest set-back follows a profit warning in October 2012 where BG stunned the market by saying there would be no production growth in 2013, despite analysts forecasting more than 10% gains.

Investors reacted more favourably to BP's (BP.) fourth quarter results which were marginally ahead of consensus. Its shares, up 1% to 467.3p, will be tested over the coming months as its oil spill trial gets underway on 25 February. Stockbroker Canaccord Genuity reckons there is a 'reasonable probability that the company manages to reach a settlement over Federal and State civil penalties before it starts.'

Semiconductor specialist ARM (ARM) hit a record high at 958.25p in the first half hour of trading on the back of full-year results. It has raised guidance for income from licences and royalties. Stockbroker Peel Hunt raised its price target from 800p to 930p but continued to question the company's valuation. At 925p, ARM trades on 46 times forecast earnings for 2013.

Virgin Media (VMED) jumped 15.6% to £28.48 after admitting it may be bought by Liberty Global (LBTYA:NASDAQ), a US-based communications group which is seeking to expand its position in Europe.

Among the mid cap fallers, media group UBM (UBM) dropped 5.8% to 738.5p after revealing a £160 million offer from Electra Partners for its data services business. Investors were clearly disappointed with the price, given that analysts initially expected a £200 million to £250 million disposal price when UBM originally announced its strategic review.

Waste disposal-to-recycling provider Shanks (SKS) dipped 2.5% to 87.75p after a flimsy trading update. It warned that growth might be curtailed in the next financial year because of tough market conditions. Shanks issued a profit warning in September 2012 because of reduced waste volumes and lower recycling prices.

Trading recommenced in failed Algerian gold miner GMA Resources (GMA:AIM) having been suspended since May 2012. The small cap wants to reinvent itself as Kemin Resources and mine tungsten and molybdenum in Kazakhstan.

Engineer Corac (CRA:AIM) had much to celebrate after revealing that its full-year results will beat market expectations. The shares jumped 10% to 14.88p. Unusual trading was noted in African Mining & Exploration (AME:AIM) which rose 21% to 4.25p without any official news. Investors may be speculating over the small cap's maiden resource statement for the Kossanto gold project in Mali which is scheduled to be published in the first half of this year.

And finally, micro cap pharmaceutical Plethora Solutions (PLE:AIM) crashed 52.5% to 2.38p after saying it is in urgent funding talks to meet working capital.

Issue Date: 05 Feb 2013