The share price of chip group Imagination Technologies sank sharply on Wednesday after the firm said that shipment growth from its partners for the second half would be at a "slightly lower rate than previously seen", due to slowing growth in the higher-end smartphone market.Oxford Instruments was a high riser after Andor Technology recommended its £176m takeover of the AIM-listed camera maker, putting concerns about a rival bid to bed.Transport firm FirstGroup gained after rebuffing "flawed" restructuring proposals from US activist investor Sandell and saying it planned to continue on its current strategy.Sector peer Stagecoach also rose after saying half-year earnings improved following a good performance from UK bus and rail and North America, adding that it is well placed for future trading.Investors at defence groups Ultra Electronics and Cobham breathed a sigh of relief today after US politicians agreed on a budget deal in Washington, providing some certainty over military spending for the next two years.Consumer products group PZ Cussons declined after foreign exchange movements limited bottom and top line growth in the first half. Revenues and operating profits were up 4% and 6% on last year, respectively, but would have risen by 6% and 8% at constant currency. FTSE 250 - RisersOxford Instruments (OXIG) 1,700.00p +8.56%FirstGroup (FGP) 121.90p +5.09%Essar Energy (ESSR) 69.95p +4.33%Bank of Georgia Holdings (BGEO) 2,229.00p +3.19%Domino's Pizza Group (DOM) 492.10p +2.95%Stagecoach Group (SGC) 371.80p +2.76%Ultra Electronics Holdings (ULE) 1,876.00p +2.46%Cobham (COB) 266.00p +2.31%RPS Group (RPS) 337.60p +2.21%Wetherspoon (J.D.) (JDW) 732.00p +2.16%FTSE 250 - FallersImagination Technologies Group (IMG) 193.50p -22.29%Soco International (SIA) 387.40p -3.99%Bwin.party Digital Entertainment (BPTY) 113.90p -3.96%PZ Cussons (PZC) 366.50p -3.58%Centamin (DI) (CEY) 43.40p -3.17%Polymetal International (POLY) 498.00p -3.11%Daejan Holdings (DJAN) 4,404.00p -2.97%Investec (INVP) 410.10p -2.91%Kenmare Resources (KMR) 19.23p -2.78%Dialight (DIA) 822.50p -2.66%BC