The FTSE 100 gained 0.19% to 7,685.33 on Thursday morning after a vote by the Fed to lift interest rates led to another record close on Wall Street.
Debenhams (DEB) plunged 19% to 28.8p after like-for-like sales fell by 1.3% on a reported basis in the 17 weeks to 30 December, with gross transaction value down 0.8%. It said early weeks of the quarter were disappointing as the market remained volatile and competitive.
In contrast, Symphony Environmental Technologies (SYM), which specialises in plastic technology, soared 17% to 15.5p on news it expects profit before tax for the year to 31 December 2017 to be significantly higher than current market expectations, and not less than £400,000, up from £123,000 in 2016.
Software provider Sopheon (SPE) also said it expects revenues, EBITDA and pre-tax profit for the year ended 31 December 2017 will exceed market expectations, sending the shares surging 17% to 422.5p.
Urban regeneration and strategic land specialist MJ Gleeson (GLE) expects first half profits to comfortably exceed last time and has maintained its full-year guidance. The share price remained flat at 792p.
Costain (COST) gained 0.7% to 468p after saying it expects full-year results to be in line with the board's forecasts after another strong performance.
Macau Property Opportunities Fund (MPO) surged 10% to 201.5p after average rentals at The Waterside grew by 6.4% between the third and fourth quarters to HK$19.85 per square foot per month. The company is hopeful that Macau's VIP gaming segment will recover further, which will facilitate the continued recovery of rental values and improve occupancy rates.