The London-headquartered packaging giant bought the family-owned Romanian group for €208m (£185m), with the acquisition expected to be completed by the end of January 2018, following Romanian competition authority approval.

Changes to staffing have not been disclosed, but the company stressed its intention to grow in Romania. EcoPack and EcoPaper will operate alongside DS Smith's existing Packaging Romania arm.

The firms are primarily focused on serving the local FMCG market, which DS Smith hopes will make the acquisition “very complementary" to its customer and asset base. It said EcoPack and EcoPaper boast high-quality packaging assets, as well as a new paper machine, built in 2017, that specialises in high-quality, lightweight paper.

DS Smith chief executive Miles Roberts said: “We continue to grow very strongly throughout Eastern Europe. This exciting acquisition will further expand our position and capability, providing an important platform for the continued development of our innovative performance packaging programme in the region.”

Roberts indicated that the acquisition would lead to further growth as well as giving DS Smith access to “significant cost synergies”. The move is expected to add to DS Smith’s earnings “immediately”.

The packaging giant already has a presence across Eastern Europe, after acquiring Duropack in 2015, which has numerous sites in the region, and with its own corrugated factory in Kielce, Poland.

DS Smith made its first entry into the US fibre-based corrugated packaging market with a $920m acquisition of Interstate Resources in June this year.

Last year, the company reported revenue of £2.4bn in the six months to 31 October 2016, up 21% on the first half of 2015. The company said this represented a 7% increase under constant currency conditions over a period, which featured acquisitions of UK POS firm Creo and Danish POS printer Deku-Pack.