Up until about 1987 Colthrop Board Mills was owned by Reed Paper and Board UK Ltd, (later Reed International) but then it became part of Reedpack, a MBO from Reed International. Reedpack was then sold to SCA in 1991 and later that year Colthrop Board Mills along with Field Packaging bought themselves from SCA and for 2 years Colthrop was part of Field Group. Then in 1991, the mill was bought by Mayr Melnhof Karton in Vienna who owned and ran the mill until it closed down in 2000.