As the access to the fossil fuels is limited, renewable energy sources have been especially intensively promoted in recent years, namely biomass. A comparatively large amount of biomass can be obtained from forests. This refers to round wood characterized by low technical quality, small−sized wood, and logging residues. Under Polish conditions, the potential amount of logging residues is estimated at 3−5 Mio. m³ per year, depending on different scenarios of their ulitization. Intense development of technologies for energy acquisition from the forest biomass has provided conditions facilitating the use of logging residues on an industrial scale. One of the possible solutions is bundling. In this process slash is compacted into cylindrical log−like units with diameter of ca. 65−75 cm and length of 2.5−3.0 m. The bundles can be forwarded to the roadside landing with standard forwarders and transported to the terminal or end−user with trucks utilized, first of all, by a round wood hauling. The John Deere slash bundler 1490D was the subject of the study. The basic unit of the bundling device was an eight−wheel forwarder. The study area was located in north−eastern Poland and comprised 10 selected plots. They represent coniferous stands, dominated by Scots pine with various fraction of Norway spruce and scattered birches. The aim of the paper was to estimate the basic technological and economic parameters of the bundling machine, working in clear cuts with two variants of logging residues concentration. In the first variant they were not especially accumulated, evenly distributed over the area. In the other one they were gathered into piles. The structure of a working day, work productivity rates, and the costs were determined. The bundler productivity rate depends largely on the extent the slash is prepared. When it is concentrated in piles, the machine does not have to travel over the entire work area to gather scattered material. In this case, the average productivity was 21.85 bundles/h. In the variant with scattered logging residues, work efficiency equaled 15.19 bundles/h. The hourly cost of the bundler use reached 289.42 PLN. The unit costs were at the level of 52.91 PLN/m³ (variant 1) and 38.54 PLN/m³ (variant 2)