Below are some of the main news-driven share price changes among FTSE 350 stocks at 12.15pm.
RISERS
Infinis Energy (LON:INFI), up 4.7%. After sharp gains yesterday morning following the release of full-year results, the stock faded badly in the afternoon session, but it is back on the rise today.
Ophir Energy (LON:OPHR), up 4.1%. Barclays has upgraded the energy firm to 'overweight' from 'equal weight', while the price target has been raised to 225p from 200p.
Paypoint (LON:PAY), up 3.3%. JP Morgan Cazenove has responded to yesterday's trading update by pushing up the target price to 985p from 950p.
FALLERS
Synergy Health (LON:SYR), down 1.7%. The US Federal Trade Commission (FTC) has informed Synergy that tit intends to block its merger with US firm STERIS.
Anglo American (LON:AAL), down 0.8%. JP Morgan Cazenove has lopped 30p off its previous 980p price target, while Liberum Capital has reduced its price target from 900p to 850p.
Rio Tinto (LON:RIO), down 0.4%. Liberum Capital has reiterated its 'sell' recommendation for the miner and cut its price target to 2,500p from 2,600p.
Below are some of the news-driven share price changes at 9.15am.
RISERS
Formation Group (LON:FRM), up 25.0%.The property development and project management company said it is trading in line with management expectations at the halfway point, while the order book is bulging. The company said it has received £1.27mln of the £6.23mln due from JV Finance Ventures.
Nostra Terra Oil & Gas (LON:NTOG), up 15.2%.The company appears to have shrugged off the worst of the crude decline, as the junior US producer and investor reported a 49% increase in revenue for 2014.
Volvere (LON:VLE), up 9.2%. The growth and turnaround investment company has seen a sharp turnaround in its own fortunes, with half-year profit before tax up to £1.65mln from £510,000 the year before.
LOSERS
Sefton Resources (LON:SER), down 22.0%. Jim Ellerton, a former executive chairman of Sefton, has lodged a complaint against the company and two of its directors, plus a former director, in the District Court of Denver, Colorado, claiming unspecified damages in connection with his resignation from the board.
Immunodiagnostic Systems Holdings (LON:IDH), down 12.3%. The diagnostic testing kit firm lowered revenue guidance for the current fiscal year. Market consensus is for sales of £47.46mln, but the company said a number somewhere in the range of £39mln to £42mln is likely to be nearer the mark.
Premier Veterinary Group (LON:PVG), down 10.1%. The former Ark Therapeutics made a half-year loss after tax of £0.4mln, though this was an improvement on the previous year's interim loss of £0.9mln.