The €634m (£531m) deal was announced five months ago.

It includes Schumacher’s corrugated converting and solid board operations in the UK, Benelux and Germany.

The UK site is in Birmingham and runs a Koenig & Bauer Durst Delta SPC 130 single-pass inkjet press for corrugated packaging.

Germany is the biggest part of the operation and is home to two “state-of-the-art mega-box plants” at Ebersdorf and Greven.

Mondi Group CEO Andrew King commented: “This acquisition significantly strengthens our corrugated packaging business, extending our footprint in Western Europe and offering strong vertical integration opportunities.

He said he was delighted to welcome Schumacher Packaging colleagues to the group.

“Together we will expand our eCommerce and FMCG offering, particularly in Western Europe, presenting exciting opportunities to introduce the group’s unique range of products to a wider array of customers as they increasingly transition towards more sustainable packaging solutions.”

Last year the Schumacher family announced a divestment strategy for its circa €1bn turnover operations in the face of growing competition from giant global groups many times its size.

The acquired operations had adjusted EBITDA of €66m last year. Mondi said this was expected to increase as new capacity at the Greven site in Germany ramps up.

It also expects to achieve €22m of cost synergies over three years.

Mondi had sales of €7.4bn last year.