FTSE 250 movers: Ophir sinks after first-half results

Africa-focused oil and gas group Ophir Energy was a heavy faller on Thursday as investors gave a cool reaction to the company's first-half report. While the firm narrowed its pre-tax loss to 19.4m dollars from 24.4m dollars previously, market chatter pinned the share-price reaction to delays in finding suitable partners for future development programmes.Thomas Cook tumbled after the head of US travel agency TripAdvisor said that summer travel trends have been weaker than expected with traffic and pricing disappointing. Thomas Cook was shrugging off a target price upgrade from Jefferies this morning, despite the broker saying it prefers the stock over sector peer TUI Travel.Construction and building materials firms were also in the red today with Keller, SIG, Barratt Developments and Taylor Wimpey all registering steep losses.Chemicals firm AZ Electronic Materials delivered a less-than-impressive set of half year results in which profits slipped 11% and the dividend was unchanged from the year before.FTSE 250 - RisersSalamander Energy (SMDR) 125.00p +1.79%Kentz Corporation Ltd. (KENZ) 467.70p +1.67%Computacenter (CCC) 517.00p +1.47%Synthomer (SYNT) 229.90p +1.28%Derwent London (DLN) 2,365.00p +0.85%Lancashire Holdings Limited (LRE) 755.50p +0.73%Interserve (IRV) 559.00p +0.54%Dialight (DIA) 1,331.00p +0.45%COLT Group SA (COLT) 102.00p +0.20%Rentokil Initial (RTO) 103.20p +0.19%FTSE 250 - FallersOphir Energy (OPHR) 340.60p -12.67%Thomas Cook Group (TCG) 147.90p -6.69%Keller Group (KLR) 1,001.00p -6.45%SIG (SHI) 176.00p -6.38%Barratt Developments (BDEV) 304.20p -6.20%AZ Electronic Materials SA (DI) (AZEM) 300.50p -5.29%Taylor Wimpey (TW.) 102.00p -5.03%Regus (RGU) 182.60p -4.90%Brewin Dolphin Holdings (BRW) 257.80p -4.73%Workspace Group (WKP) 434.30p -4.53%BC