After failing to find a buyer for its diamond business, diversified miner Rio Tinto (RIO) is rumoured to be preparing to list the unit in London later this year. Its shares added 3p to £28.60 following weekend press reports about the possible event.


Corporate governance disaster Eurasian Natural Resources (ENRC) nudged ahead 1.3% to 242.9p ahead of today's 5pm takeover deadline. The miner's three billionaire founders last month secured extra time to put together a bid for the troubled business. Analysts reckon the interested parties may ask for another extension later today.


Costain (COST) advanced 1.8% to 260p after winning a £60 million contract to strengthen London's Hammersmith Flyover. The construction group is a running Shares Play of the Week trade, having highlighted the stock last summer ('buy' at 213.8p, 5 July 2012).


Analysts continue to get more bullish about electronics seller Dixons Retail (DXNS) with stockbroker Cantor upgrading its price target from 42p to 50p. Alas, this didn't have the desired effect on today's share price, slipping 0.8% to 41.19p. Dixons is a running Shares Play of Week where we highlighted the stock's potential at 31.1p two months ago (11 Apr).


Impressive full-year results from identity security specialist GB (GBG:AIM) reveal a 24% rise in sales and 40% hike in profits. Part fueled by acquisitions, the £107 million cap is tapping several growth spaces and is on the lookout for new buy-and-build opportunities. Despite the strong results, the shares dipped 1.5% to 97.5p as its high rating (low-20s price/earnings multiple) caps its ability to catch the eye of new investors.


One-click mobile payments specialist Bango (BGO:AIM) has arrested short-term weakness with news that it will power the payments for the forthcoming Firefox apps store from web browser Mozilla. The announcement is typically light on revenue implications. Read Shares' March interview with CEO Ray Anderson here.


2D and 3D x-ray imaging specialist Image Scan (IGE:AIM) soared 30% to 3.25p after unveiling £1 million worth of new business since early April. The £2.5 million microcap made £4.3 million of revenues last year and its first profit of £108,000.


Shares in carbon-based materials developer Graphene Nanochem (GRPH:AIM) skidded 13.5% down to 93p on red ink-laden 2012 results. But the numbers are fairly meaningless given the subsequent £32.5 million fund raising, a reverse into the old Biofutures business and, most important, the acquisition of Malaysian Platinum NanoChem.

Technical problems with one of All Leisure's (ALLG:AIM) ships has forced one cruise to be cut short and another to be cancelled. There's no news on the financial impact of these events but the market is clearly worried as the shares dropped 11.1% to 32p.


Advanced Oncotherapy (AVO:AIM) jumped 13.9% to 1.85p after partnering with BMI Healthcare to make 'state-of-the-art' affordable cancer treatment more widely available to patients in the UK.


Shares in oil and gas explorer Range Resources (RRL:AIM) moved 8.7% higher to 3.07p after announcing strong flow test results from a well in Guatemala.


Fuel technology specialist Quadrise Fuels (QFI:AIM) was in gear, gaining 2.4% to 13.6p after signing a memorandum of understanding with Colombian oil producer Ecopetrol and Dallas firm Nexidea to explore opportunities in South and Central America.


UK unconventional gas play IGas (IGAS:AIM) gushed up 8.1% to 100.5p after revealing technical studies put the potential of its assets in the Bowland shale in Lancashire at between 15.1 trillion cubic feet (tcf) to 172.3 tcf.


Media tiddler DCD Media (DCD) fell 18.5% (9 Jun) on news that the £7 million cap has raised £930,000 through the issue of convertible loan notes. Investors fretted about the dilutive impact should these notes be converted into equity.

Issue Date: 03 Jun 2013