Lufthansa - the region's largest combination airline group in terms of cargo - saw freight traffic for the period decline by 2.9 per cent year on year to 904 million revenue cargo tonne kms.
This is the second month in a row that the German airline group has recorded a decline and compares with its year-to-date growth rate of 2 per cent.
While demand decreased, the amount of cargo capacity on offer from the group was up by 1.8 per cent and as a result its load factor for July slipped to 64.1 per cent against 67.2 per cent this time last year.
IAG Cargo, made up of the cargo capacity of British Airways, Iberia and Aer Lingus, also saw cargo traffic slip during the month - it recorded a 3.1 per cent decline for July to 462 million cargo tonne kms.
The airline group has registered declines in cargo traffic in five of the first seven months of the year and its year-to-date performance stands at a decline of 0.9 per cent.
In its latest market update, IATA said that European airline performance is being affected by a slowdown in export orders, while supply chain bottlenecks, which often result in a boost in air cargo demand, have eased.
Performance for the month was better at Air France KLM and Finnair, although comparisons at both airlines are affected by fleet changes.
Air France KLM's July cargo traffic increased by 4.6 per cent year on year to 737 million revenue tonne kms. This compares to a decrease of 0.3 per cent over the first seven months of the year and is the biggest increase since last year's peak season, reports London's Air Cargo News.
Performance over the last couple of years at the group has been affected by changes to its fleet. This year the airline has replaced three of its Boeing 747 combi aircraft with B787s, while ongoing strike action by Air France staff resulted in the cancellation of flights earlier this year.
Finnair saw cargo traffic increase by 2.8 per cent year on year to 90.7 million revenue tonne kms. This is slightly ahead of its performance over the first seven months, when cargo traffic increased by 2.2 per cent.
Capacity increased by 7 per cent during the month due to the use of larger aircraft. The airline said it benefitted from growth in Japanese volumes, offset by the ending of deal to rent space from Japan Airlines.