Video games and consoles retailer Game Group saw shares tumble after it revealed half-year losses of £18.8m.
The group's plunge into the red compared with underlying pre-tax profits of £14.5m a year earlier and came after it suffered a 16.2% slide in UK and Ireland sales during the six months to July 31.
Game, which recently hired former Vodafone retail boss Ian Shepherd to help revive its fortunes, said like-for-like sales declines had since eased and raised hopes of a better second half.
But the news failed to ease shareholder concerns, with shares slumping more than 13%.
Game, which has around 10 stores in Northern Ireland, warned in June that sales were expected to fall throughout 2010, with its first half hit by a cyclical downturn in the market as well as stiff competition.
A stronger Christmas line-up of software releases and new motion sensing technology looks set to return the market to growth.
Game said sales declines were improving as the year progressed, from 17.2% in the first 19 weeks to 14.8% in the 34 weeks to date across the UK and Ireland.
While it is expected to report profits at the full year stage, analysts said forecasts would move lower after today's worse-than-expected results.
Game has endured a tumultuous year, with former chief executive Lisa Morgan and chief operating officer Terry Scicluna quitting in recent months.
Game is restructuring its UK and Ireland store base, where it trades as Game and Gamestation.