Chip maker Imagination Tech plummeted after warning that profits would fall below expectations after delays to several deals hit licensing revenues. Multinational energy and environmental consultancy company RPS Group also fell sharply after saying that a slowdown in investment in resource projects in the Australia-Asia Pacific region has "reappeared". Liberum Capital downgraded the stock to 'hold'. Meanwhile, shares in NMC Health were rebounding one has after being hit with a downgrade from Numis Securities, which changed its rating on the stock from 'buy' to 'hold'. FTSE 250 - RisersNMC Health (NMC) 288.60p +4.30%Telecity Group (TCY) 959.50p +3.73%Britvic (BVIC) 458.00p +3.15%Ocado Group (OCDO) 172.70p +2.80%Perform Group (PER) 520.00p +1.76%Carillion (CLLN) 276.80p +1.76%Filtrona PLC (FLTR) 725.00p +1.68%New World Resources A Shares (NWR) 153.30p +1.52%Lonmin (LMI) 267.60p +1.52%Hochschild Mining (HOC) 250.60p +1.46%FTSE 250 - FallersImagination Technologies Group (IMG) 317.60p -25.18%RPS Group (RPS) 222.10p -11.51%Inmarsat (ISAT) 686.50p -8.34%Heritage Oil (HOIL) 143.10p -5.73%Homeserve (HSV) 206.50p -4.44%Dunelm Group (DNLM) 820.50p -3.75%Bodycote (BOY) 501.50p -3.65%Carpetright (CPR) 622.00p -3.57%Petra Diamonds Ltd.(DI) (PDL) 105.20p -3.49%Computacenter (CCC) 444.00p -3.46%NR