In a statement published on its Facebook page, Lecht 2090 said it did not know what caused the malfunction at 3.25pm on Tuesday.
The chairlift, which is the only lift of its kind at Lecht Ski Centre near Tomintoul, Aberdeenshire, is expected to remain closed for some time. The Health and Safety Executive is investigating.
Three of the injured group were airlifted from the ski slope while the others were taken by ambulance.
Grampian Police, fire service and mountain rescue teams assisted with the rescue.
A spokeswoman for the Lecht centre said 36 other people who were stranded on the chairlift were rescued after the accident.
Many skiers and snowboarders, including families, returned to Lecht yesterday undeterred by the incident.
Enthusiasts in 20 vehicles made the trip to the resort early yesterday before the road was closed because of snow.