The sale, revealed in DMGT's full-year results, will include its ten print sites and the 50m Elsham Wold press project, as well as 100 newspaper titles.

DMGT said that it has begun exploring opportunities for the divestment, to decide whether "greater shareholder value" could be produced by selling the division.

In its 2005 results, NNG posted 19.6% operating profit of 102m, on turnover of 520m. DMGT's national newspaper arm, Associated Newspapers, by contrast, posted 10.8% operating profit of 95m, on a turnover of 877m.

The announcement of the sale comes just six months after DMGT launched a two-year cost-cutting programme, aiming to reduce NNG's outgoings by 20m per year.

A 100m investment in print restructuring, including the closure of an aging plant in Exeter during the summer and the project at Elsham Wold in north Lincolnshire, formed a major part of that programme.

Private equity houses are believed to be the most likely bidders for the group, while rivals Johnston Press, Trinity Mirror and Newsquest are the probable trade bidders.