The market has held on to early gains led by paper and packaging group Mondi and information technology services firm Computacenter.Centamin Egypt continues to rise after the results of the Sukari project scoping study showed that the gold miner can more than double the capacity of its process plant and deliver strong returns over a long mine life.The weather is pressuring down many companies with trendy retailer SuperGroup and bingo club operator Rank among the worst performers of the day.CPP is heading lower despite saying that trading is in line with expectations. Peel Hunt raised the target price for the credit card and ID theft specialist but downgraded its rating to a 'hold'. The broker notes that the shares have risen 34% since August and are now fairly priced.FTSE 250 - RisersMondi (MNDI) 507.50p +4.62%Centamin Egypt Ltd. (CEY) 173.70p +4.45%Computacenter (CCC) 403.40p +4.02%Chemring Group (CHG) 2,962.00p +3.60%Punch Taverns (PUB) 76.50p +3.31%Impax Environmental Markets (IEM) 126.70p +3.01%John Wood Group (WG.) 554.50p +2.97%Regus (RGU) 84.75p +2.79%Elementis (ELM) 137.00p +2.70%Kenmare Resources (KMR) 26.82p +2.60%FTSE 250 - FallersSupergroup (SGP) 1,282.00p -3.90%Rank Group (RNK) 133.50p -3.61%CPP Group (CPP) 296.00p -2.95%Shanks Group (SKS) 123.40p -2.06%Marston's (MARS) 109.40p -1.97%Hikma Pharmaceuticals (HIK) 800.50p -1.96%Victrex (VCT) 1,483.00p -1.92%Renishaw (RSW) 1,282.00p -1.84%Daejan Holdings (DJAN) 2,672.00p -1.66%Kesa Electricals (KESA) 161.80p -1.34%