Heritage Oil topped the FTSE 250 risers after Uganda's government approved the delayed sale of the oil explorer's assets to Tullow Oil.The sale was delayed because of a dispute between Heritage Oil and the Ugandan government about the level of tax to be paid. But now the Ugandan government said a resolution had been made between the two parties. N Brown is one of the major fallers after the internet and catalogue home shopping company posted weaker than expected sales figures and said trading since the general election has been subdued.In the 18 weeks ended 3 July, total group revenue increased by 1.1% with sales 0.1% ahead on a like for like basis. In the 8 weeks to 24 April, N. Brown reported a 4.1% like for like sales increase.FTSE 250 - RisersHeritage Oil (HOIL) 411.60p +8.89%Inchcape (INCH) 260.40p +7.69%Galiform (GFRM) 62.65p +6.91%GKN (GKN) 119.60p +6.69%Talvivaara Mining Company (TALV) 385.30p +6.52%Spirax-Sarco Engineering (SPX) 1,437.00p +5.82%Persimmon (PSN) 368.80p +5.82%Ferrexpo (FXPO) 251.50p +5.76%Taylor Wimpey (TW.) 26.50p +5.75%Weir Group (WEIR) 1,109.00p +5.72%FTSE 250 - FallersBrown (N.) Group (BWNG) 244.50p -4.08%CPP Group (CPP) 255.00p -3.77%Moneysupermarket.com (MONY) 70.00p -2.78%Promethean World (PRW) 175.90p -2.33%BH Global USD Shares (BHGU) 11.1 -2.03%JD Wetherspoon (JDW) 401.80p -1.98%Gem Diamonds (GEMD) 216.10p -1.77%Atkins (WS) (ATK) 672.00p -1.75%Fidessa (FDSA) 1,322.00p -1.34%Unite Group (UTG) 170.10p -1.28%