(Sharecast News) - Online retailer MySale expects the first half of its trading year to result in a loss due to inventory issues and recent changes to Australian goods and services tax regulation.MySale, which operates across Australia, New Zealand, South East Asia and the UK, told investors on Friday that revenues had dropped 17% across the group to AUD $126m in the six months ended 31 December, dragging gross profits down by 35% to $29.5m as a result.The AIM-listed outfit expects to report an EBITDA loss of AUD $5m - a marked turnaround from the $5.5m profit recorded a year earlier.Gross margins also narrowed to 23.4% from 30.2%.MySale primarily attributed the loss to market disruptions caused by changes to Australian GST regulation, together with product mix and inventory issues, but also noted that revenue had been impacted by the group's planned reduction in its offline activities.Looking forward, MySale said it was "confident" that its action plans would deliver an "improved performance in the second half" and that its full-year outcome would be in line with market expectations.Chief executive Carl Jackson said: "Whilst performance during the first half of the year has been disappointing, we have taken immediate action to address the issues.""We believe the reconfigured business will be stronger, more efficient and continue to provide a compelling consumer offer and deliver unique solutions to our brand partners."As of 0820 GMT, MySale shares had sunk 11.45% to 20.10p.