Mitchells and Butlers was a top riser this morning after the owner of the O' Neills and All Bar One pub chains reported a pick-up in like for like sales in the late summer, but the shares have since lost a bit of fizz and are no longer in the top 10.Oil stocks Salamander Energy and Melrose Resources are higher despite the lower crude price, but North Sea focused EnQuest is among the heaviest fallers. Asset manager Henderson Group falls after a downgrade to 'hold' from 'buy' at Citigroup. FTSE 250 - RisersKenmare Resources (KMR) 20.00p +5.26%Aberdeen Asset Management (ADN) 154.50p +3.76%St. Modwen Properties (SMP) 167.50p +2.95%Avis Europe (AVE) 212.80p +2.80%CPP Group (CPP) 271.20p +2.65%Salamander Energy (SMDR) 250.40p +2.62%Xchanging (XCH) 140.90p +2.47%Premier Foods (PFD) 17.95p +1.93%Unite Group (UTG) 200.50p +1.78%Melrose Resources (MRS) 294.80p +1.66%FTSE 250 - FallersHenderson Group (HGG) 122.90p -5.61%Cable & Wireless Worldwide (CW.) 73.65p -3.47%Howden Joinery Group (HWDN) 72.50p -3.33%Babcock International Group (BAB) 530.50p -3.11%Ferrexpo (FXPO) 285.00p -2.90%easyJet (EZJ) 377.00p -2.46%Gartmore Group (GRT) 112.00p -2.44%EnQuest (ENQ) 112.80p -2.34%COLT Group S.A. (COLT) 118.10p -2.24%PartyGaming (PRTY) 280.00p -2.20%