primarily attributable to the impact of the COVID-19 pandemic and affected all operating segments, whereby the business in Switzerland was relatively less affected. In line with the decreased shipments, sales also fell more sharply due to lower price levels, down by 21.2% from EUR 4.9 billion to EUR 3.9 billion.
Adjusted for material special effects, Group operating income declined from EUR 110 million in the prior-year period to EUR 72 million in the first nine months of the 2020 fiscal year, also largely as a result of the pandemic. EBITDA was further negatively impacted by material special effects of EUR 73 million, primarily related to personnel measures. Consequently, the net loss was considerably higher than the prior-year figure of EUR 4 million at EUR 136 million.
OUTLOOK FOR THE REMAINDER OF YEAR
Due to rising COVID-19 infection figures, uncertainty remains with regard to the further development of shipments in 2020. Due to seasonal patterns, we expect that shipments and sales in the fourth quarter will be down on the previous quarter. Based on our well-advanced digitalization and the consistent implementation of our Surtsey transformation project - along with the associated cost effects, which are already beginning to become visible - we anticipate EBITDA before material special effects of EUR 75 million to EUR 95 million for the 2020 fiscal year. We also expect a significantly positive cash flow from operating activities.