Palm Paper, a subsidiary of Germany-based Papierfabrik Palm, switched on the PM7 machine at its King's Lynn site in Norfolk on 21 August.
The machine, which has a net width of 10.63m, is set to produce 400,000 tonnes of newsprint each year for standard, flexo and heatset applications – all from 100% selected recycled fibre.
Palm Paper managing director Derek Harman said: "We want to stabilise production and carry out further trials to check that the quality is up to scratch on such a large machine."
He added that he hoped consumption of newsprint would "stabilise" in the coming months.
"With the King's Lynn plant, we have taken the view that in the next 40 years, demand will be good and bad. We are in this for the long term," he said.
Some 150 staff work at the site, which received planning permission from King's Lynn and West Norfolk Borough Council in November 2007.
Put your palms together for Palm Paper – Associate editor Jo Francis on what this news means for mills in the UK