TDC, the Danish telecoms group, has taken an important step towards a planned share sale by its private equity owners next year by agreeing to sell Invitel, its debt-burdened Hungarian subsidiary, in a deal valued at about €700m ($1bn).

Invitel, which TDC acquired in a debt-funded deal near the peak of the market bubble in January 2007, has been hit recently as the value of its revenues in Hungarian forints has fallen compared with its euro-based debts.