Belgium's TNT Airways has unveiled plans to replace 10 Boeing 737-300 freighters currently deployed on its European network with 11 larger-capacity 737-400 Special Freighters.
The first aircraft of the type is due to be delivered shortly.
Each of the -400s is being converted from passenger to freighter configuration by Israel's IAI at its bases in Tel Aviv, Israel and Canton, in China.
The delivery schedule will run from October 2010 to the first quarter of 2012.
The 737-400SF can carry one more container, or an additional 2.5t, of payload than the 737-300F.
At the end of next year, TNT Airways will take delivery of its first Boeing 757-200 Combi, the first to be certified in Europe. The aircraft will be dedicated to a service contract with NATO starting in January 2012.