Dana Petroleum rallied after it confirmed last night that it is in talks with a potential bidder, widely reported to be South Korean national oil company KNOC. The shares are up almost 20% today valuing Dana at about £1.3bn. The talk is of a bid being worth around £1.5bn though Dana said the discussions are very early stage. Premier Oil is higher in sympathy.Brit Insurance is playing hard to get in its courtship with US private equity firm Apollo. The US outfit has told Brit Insurance it may be prepared to up its £10 a share bid by 50p, but the underwriter thinks this still undervalues the business. The firm’s shares are also up.Builders' merchant Travis Perkins gained on news that it has seen a strong rebound in trading since March. The Wickes owner now expects its first half will beat its expectations while dividends will resume again with a 5p interim. Group revenue for the six months ended 30 June was up by 4.7%, with like-for-like sales up 3.4%. Like-for-like turnover in the last two months was 10.3% ahead in Merchanting and in the last 9 weeks 1.6% ahead in Retail. FTSE 250 - RisersDana Petroleum (DNX) 1,406.00p +19.46%Lamprell (LAM) 222.00p +8.35%Premier Oil (PMO) 1,306.00p +6.53%Laird (LRD) 104.50p +5.77%Travis Perkins (TPK) 747.50p +5.43%Wellstream Holdings (WSM) 460.00p +4.55%Brit Insurance Holdings NV (BRE) 927.00p +4.45%Cookson Group (CKSN) 383.00p +4.25%JD Sports Fashion (JD.) 759.50p +4.04%John Wood Group (WG.) 323.40p +4.02%FTSE 250 - FallersGrainger (GRI) 112.00p -2.61%Hansen Transmissions International (HSN) 69.65p -2.31%Renishaw (RSW) 715.00p -1.52%Mothercare (MTC) 523.00p -1.41%Gartmore Group (GRT) 101.70p -1.26%Game Group (GMG) 62.25p -1.19%Dunelm Group (DNLM) 330.00p -1.08%TR Property Inv Trust (TRY) 134.70p -1.03%Helical Bar (HLCL) 263.90p -0.90%Hays (HAS) 89.10p -0.89%