A Welsh Government-backed environmental body is looking to appoint a maximum of 20 contractors onto a civil engineering framework.
Natural Resources Wales is launching the framework, which is valued between £15m and £20m and will last for four years.
It covers the construction and maintenance of access tracks, roads, bridges, paths and other harvesting facilities in forests and woodlands throughout Wales that Natural Resources Wales manages.
The framework is divided into two lots: the first is for the construction of primary estate infrastructure and is valued between £6m and £10m; the second is for the construction of secondary infrastructure including maintenance, repair and reinstatement of all aspects of estates infrastructure and is valued between £10m and £15m.
Natural Resources Wales is procuring on behalf of 13 Welsh local authorities and Dyfed-Powys Police.
The deadline to tender is 30 September 2016.
Other framework opportunities in the principality include an £850m framework procured by councils across Wales.
Successful contractors will cover design-and-build jobs for a wide range of clients, including Aberystwyth University, the National Library of Wales, Dyfed Powys Police and Swansea City Council.