Telecity's shares slumped on Tuesday after announcing the departure of chief executive Michael Tobin who has been with the company for more than 10 years. Tobin will leave in October following a handover period on 31 October. It comes shortly after Eric Hageman was appointed chief financial officer to replace Brian McArthur-Muscroft who left in January.Regus, the Luxembourg-based provider of office outsourcing services, was also lower after it saw its pre-tax profit for the first half of 2014 fall slightly from £31.1m in the same period in 2013 to £31.0m in the six months ended June 30. The flat profit came despite a 16.9% increase to £804.7m in revenue at constant currency, and a 41% rise to £39.9m in operating profit at constant currency.On the upside, Ocado tracked top tier supermarket stocks higher, while energy peers Cairn and Ophir were also both in the top 10. Stagecoach shares motored higher after the group released its quarterly statement, in which it said that all its businesses lifted revenue in the last three months, particularly its London bus contract operation which achieved an increase of 14.4% as it secured new work. Panmure Gordon drove further gains after it said Stagecoach remains one of its preferred stocks in the transport sector. South African platinum miner Lonmin was also rising after it issued a statement saying there was no foundation to media speculation about plans to restructure the business. It also said its ramp-up following the strike action was progressing ahead of its expectations. FTSE 250 - RisersPerform Group (PER) 208.00p +6.67%RPS Group (RPS) 285.60p +4.08%Ocado Group (OCDO) 391.60p +3.49%Cairn Energy (CNE) 188.60p +3.34%Ophir Energy (OPHR) 228.00p +3.17%AO World (AO.) 228.80p +3.02%Thomas Cook Group (TCG) 128.90p +2.96%Bellway (BWY) 1,654.00p +2.86%CSR (CSR) 570.50p +2.79%NMC Health (NMC) 492.40p +2.58%FTSE 250 - FallersTelecity Group (TCY) 709.00p -6.89%Regus (RGU) 184.00p -6.36%Centamin (DI) (CEY) 60.85p -4.55%Computacenter (CCC) 600.50p -2.83%Ferrexpo (FXPO) 134.60p -2.46%Fisher (James) & Sons (FSJ) 1,345.00p -1.97%Petra Diamonds Ltd.(DI) (PDL) 179.10p -1.92%Cineworld Group (CINE) 330.40p -1.75%Workspace Group (WKP) 619.00p -1.43%Fidessa Group (FDSA) 2,308.00p -1.28%NR