Sports Direct sales rose 2.9% to £687.7m for the 26 weeks to October 26, boosted by international sales. UK retail sales dropped 1.6% to £510.1m.
Sports Direct's UK wholesale and other revenue was also down, by 65.9% to £7.9m over the period.
Underlying profit before tax was up 3% to £51.8m for the period. This excluded a net foreign exchange gain of £45.4m over the period. Reported profit before tax was therefore up 360.8% to £97.7m.
Sports Direct added a net eight new stores during the half, with 14 openings and six relocations, and closed 23 stores. Sports Direct had a total of 366 UK stores at October 26.
Sports Direct said it planned to open 20 stores this year.
International retail sales increased by 34.5% to £51.8m. This was around 17% growth excluding the impact of foreign currency exchange rates. The branded division, which includes wholesale and licensing revenue was up 34% to £117.9m.
Group margin increased by 10 basis points to 43.4%.
Sports Direct said that trading since October was in line with expectations, and that EBITDA for the year would be in line with expectations at £135m.
Sports Direct chief executive Dave Forsey said: "These are a solid set of results in what was a very tough trading period. These results reflect the resilience of our flexible business model and the focused approach towards the core principals of retailing."
He added that the business had also improved relationships with its key brands, including Nike, Adidas and Puma.
Forsey declined to comment on the investigation by the Office of Fair Trading into a possible merger of Sports Direct and JJB Sports.