BERLIN, July 10 (Xinhua) -- High demand for the online mail order services of German courier companies increasingly pose a logistical challenge for the industry, a study published on Tuesday by the Federal Association of Packaging and Express Logistics Firms (Biek) finds.

According to the Biek study, the number of mail-ordered packages delivered by companies reached the record annual level of 3.3 billion thanks to booming e-commerce in 2017. The figure marked an increase of 6.1 percent compared to the previous year and a near doubling of volume compared to the year 2000.

Biek highlighted that its companies increasingly struggled to find delivery drivers which in turn pushed up the wages which had to be paid to staff. Additionally, the quality of services was suffering on account of growing traffic congestion in German cities and towns.

The courier services represented by Biek expect the trend to continue into the near future with the number of packages sent annually reaching 4.3 billion in 2022. The study noted that companies were already experimenting with different ways of ameliorating related pressures on their business models.

A group of five large courier services in Berlin are cooperating in a joint venture to utilize traditional delivery bicycles again while sharing a centralized transshipment center. By contrast, Deutsche Post DHL Group hopes to rely more on its fleet of fully-electric "Streetscooter" vans which it has developed together with U.S. carmaker Ford and is also offering for sale to third parties.

Such investments in response to logistical challenges and fierce competition between courier services have placed a heavy financial burden on the industry with gross earnings increasing slower than new orders in 2017 (plus five percent). As a consequence, the average revenue measured by Biek per package declined from 5.85 euros to 5.78 euros (6.78 U.S. dollars) between 2016 and 2017.