LONDON — I believe the shares of security group G4S plc (LON:GFS) should continue their impressive ascent of recent months. The gigantic firm, which has more than 340,000 employees spread across more than 100 countries, is ready to rocket still higher on accelerating activity in new territories. Indeed, broker Investec has hiked its price expectations for the firm to 330 pence from 280 pence in recent days, representing 16% upside from current levels. Olympic struggle at an end G4S announced last week that it had reached a financial settlement with the organizers of the London 2012 Olympic and Paralympic Games. The final sum — owed as a result of the company's inability to adequately staff the events — will cost some 70 million pounds, up from the previously estimated 50 million pounds. Last year's sporting fiasco caused G4S' shares to shake frantically at times, exacerbated by the loss of a number of public-sector opportunities with the U.K. prison and police services.