Merger activity once again ruled market sentiment with water and waste management group Northumbrian Water and defence group QinetiQ coming into focus. Northumbrian Water confirmed that it received an offer proposal from Hong Kong infrastructure group Cheung Kong. The statement comes after Cheung King said on Monday that it was in the initial stages of sizing up an offer for the north-east England-based utility. Shares of QinetiQ jumped more than 6% on rumours that it was being targeted by a U.S.-based defence firm. The Evening Standard said that the U.S. firm was mulling a 190-a-share approach for QinetiQ. On the flipside, shares of Premier Foods continued its downward slide, a day after it warned of a significant drop in profits, prompting brokerage Panmure Gordon to slash its target price for the Hovis bread and Branston pickle maker. Other food retailers like Associated British Foods and Cranswick also struggled to gain momentum. FTSE 250 - RisersQinetiQ Group (QQ.) 128.50p +6.46%Tullett Prebon (TLPR) 376.30p +6.21%Stagecoach Group (SGC) 269.60p +5.60%Imagination Technologies Group (IMG) 395.50p +4.88%Morgan Crucible Co (MGCR) 322.40p +4.71%International Personal Finance (IPF) 385.00p +4.65%Heritage Oil (HOIL) 229.30p +4.51%SThree (STHR) 413.00p +4.03%Telecom Plus (TEP) 690.00p +3.76%SIG (SHI) 141.60p +3.74%FTSE 250 - FallersPremier Foods (PFD) 17.22p -9.46%ITE Group (ITE) 212.60p -2.61%London Stock Exchange Group (LSE) 1,037.00p -2.26%Anglo Pacific Group (APF) 312.40p -2.16%Kenmare Resources (KMR) 57.70p -2.12%Hochschild Mining (HOC) 450.00p -2.09%Shanks Group (SKS) 125.60p -1.72%Carpetright (CPR) 640.00p -1.69%Berendsen (BRSN) 536.00p -1.65%Supergroup (SGP) 850.00p -1.39%