Engineering group Charter International fell back on Wednesday morning, despite sector peer Melrose saying it is working on a better takoever offer for the company.Charter's shares shot up yesterday after it confirmed speculation that it has received a rival offer to the one from Melrose.Christopher Miller, chairman of Melrose, said: "Following the Charter announcement yesterday we have asked Charter to cooperate in a diligence process and to lengthen the "put up or shut up" timetable to assist us in presenting an offer for their shareholders' consideration."The economic divide between London and the rest of the UK appears even to extend to the student accommodation sector, judging by Unite Group's half year results. In the six months to 30 June, the company's diluted net asset value climbed to 310p a share from 295p at the beginning of the year. The value of the group's stabilised property portfolio grew by 2.1%, with rental growth in the first six months delivering £15m of net valuation uplift. Despite talk of deep cuts in the university sector, Unite said that 89% of its rooms are reserved for the coming academic year, against 87% at the same last year.FTSE 250 - RisersUnite Group (UTG) 164.70p +7.72%Kenmare Resources (KMR) 42.99p +6.78%Filtrona PLC (FLTR) 334.00p +6.07%Croda International (CRDA) 1,744.00p +5.19%Aquarius Platinum Ltd. (AQP) 240.70p +5.02%Carillion (CLLN) 326.50p +4.88%Dixons Retail (DXNS) 11.87p +4.31%Intermediate Capital Group (ICP) 223.60p +4.29%Elementis (ELM) 141.60p +4.19%Michael Page International (MPI) 377.10p +4.03%FTSE 250 - FallersPremier Foods (PFD) 13.13p -4.99%William Hill (WMH) 211.20p -3.61%Charter International (CHTR) 722.50p -3.28%Amlin (AML) 299.50p -2.89%Atkins (WS) (ATK) 525.50p -2.59%Enterprise Inns (ETI) 38.41p -2.09%Daily Mail and General Trust (DMGT) 378.80p -2.04%Phoenix Group Holdings (DI) (PHNX) 518.50p -1.89%Euromoney Institutional Investor (ERM) 565.00p -1.82%Anglo Pacific Group (APF) 291.10p -1.59%--jh