The Enquirer understands the sale is expected to raise at least £2.25m.
More than 600 pieces of kit are being offered for sale by national asset and property consultancy Lambert Smith Hampton (LSH).
Aspin Group went into administration last month.
The former piling specialist’s assets include Colmar and Liebherr road/rail vehicles, excavators, drilling rigs, piling attachments and rail trailers.
The online auction is now live here and will close on September 12 at 3pm.
Roland Cramp, Director of Machinery & Business Assets, at LSH said: “Aspin operated an excellent range of modern, well-maintained plant and we have already received a large number of enquiries from across the construction industry.”