The FTSE 250 pulled back from yesterday's gains on Wednesday as worries about the health of another Eurozone country, Portugal came into focus after Moody's Investors Service downgraded the country's credit rating to junk. The index tracking the blue-chip stocks also tumbled below the 6,000 points mark, which weighed on investor sentiment. On the company news front, Dublin-based Kenmare Resources, a mineral miner that has operations in Mozambique, slumped more than 6% after Mozambique's Mineral Resource minister Esperanca Bias announced plans to revise the mining law. In contrast, cash and carry wholesaler Booker Group said it is on track to meet expectations for the year ending 30 March, and reported stellar first-quarter sales, bucking the trend seen by other retailers. Direct home shopping company N Brown Group's shares rallied for the second straight day after it reported robust revenue growth, defying the pressures of a weak economy.FTSE 250 - RisersBooker Group (BOK) 75.65p +7.38%Brown (N.) Group (BWNG) 285.50p +6.65%JD Sports Fashion (JD.) 1,044.00p +6.53%WH Smith (SMWH) 520.00p +4.00%Supergroup (SGP) 948.50p +3.72%Carpetright (CPR) 654.00p +3.40%Dunelm Group (DNLM) 406.70p +3.30%Sports Direct International (SPD) 250.40p +3.26%Domino's Pizza UK & IRL (DOM) 428.50p +2.93%Mothercare (MTC) 431.00p +2.59%FTSE 250 - FallersKenmare Resources (KMR) 55.95p -6.52%Ferrexpo (FXPO) 468.20p -5.47%Thomas Cook Group (TCG) 127.40p -3.99%De La Rue (DLAR) 746.00p -3.31%Pace (PIC) 110.50p -2.56%Babcock International Group (BAB) 713.50p -2.26%Lancashire Holdings (LRE) 650.00p -2.26%EnQuest (ENQ) 127.80p -2.14%New World Resources A Shares (NWR) 909.50p -2.05%RPC Group (RPC) 377.20p -1.98%